Denis Island, Seychelles - environmental update

Turtle nesting season 2010

2010-11-19T21:40:00.000-08:00

The hawksbill turtles (kare) and the Green Turtles (torti ver) are the most common marine turtles known by most Seychellois. On rare occasions the loggerhead (torti nanmkoyo) and the leather turtles (torti karanbol) can be seen as passers-by in our waters.

Is it true that time is running out for our turtles?

For us to understand this question, let us ask ourselves few simple questions: When was the last time you saw a turtle nesting on beach? When was the last time you saw turtle hatchlings rushing down the beach to the sea? What has been done to ensure that time is not running out for these charismatic creatures which wander our underwater world?

The turtle nesting season this year started quietly for many important nesting beaches in the Seychelles. The friends of the turtles all over our islands have been actively gearing up for this year’s nesting season and have been on the lookout to monitor the turtles coming ashore with the egg clutches. In some areas, sightings have been few; some beaches have been graced by the presence of the tracks while some have sheltered the eggs freshly laid by the females. Some females can come up several times to lay up to eight clutches during one nesting season.On Denis Island, turtles have been sighted numerous times; green turtles have been seen once late afternoon nesting and other times only the tracks and huge pits have been observed all around the island. Amazingly, over 10 pits were seen on a narrow stretch of the beach close to the lighthouse. Since early October, active monitoring for the hawksbill turtles have started; some walks have been spectacular as the turtles were found up the beach front. Other times, only the tracks could be seen. For the avid nature lovers who happened to be on the beach early Tuesday 2nd November, they were able to experience first hand a hawksbill turtle coming up on the beach, searching for the ideal spot, nest and returned back to the sea.

There were lots of “WOW”, “C’est merveilleux” as well as interesting questions about the biology and ecology of this charismatic organism. Early that same day, a nice couple happened to have their own private show of another turtle nesting and they videoed it as souvenir to take home.
Active monitoring is still ongoing and we are all patiently waiting for the first batch of hatchlings to emerge hopefully within the next month or so. Whether you are just a picnicker, a beach bum or just happen to wander around on a beach, keep an eye for any tracks and your ears open for any sand throwing all over the place, especially among the Scaevola sp. Inform a local who will take note of this organism’s status, as such information is valuable to further enhance its protection as well as provide additional knowledge of its ecology.

Eradication of Common Mynas from Denis Island, Seychelles, 2010 (Courtesy Prof. Chris Feare)

2010-08-12T04:46:00.000-07:00

An attempt to eradicate Common Mynas Acridotheres tristis from Denis Island, Seychelles, began in late May 2010. The justification for the present control is evidence that mynas are directly and indirectly impacting negatively on the populations of some of the introduced endemic birds. An earlier attempt had been made, mainly using Starlicide (a toxicant that demonstrates some specificity to certain bird families, including mynas) in the early 2000s but this attempt was abandoned after a contemporaneous rat eradication attempt had failed; a subsequent rat eradication was successful. Now that four species of Seychelles endemic bird have been introduced to Denis, this toxicant is considered too dangerous for the endemics to be used as a primary control measure and the current attempt to remove mynas is centred on trapping.
In the initial stages two kinds of trap were built and tested: funnel traps, which rely on attractive food to entice mynas into the traps, and decoy traps, which use a live decoy myna in a central compartment to attract nearby mynas. Mist nets were also used in initial trials where flocks of mynas concentrated, as were fine nylon nooses placed on the ground among bait. In trials, only decoy trapping proved effective and the eradication attempt now relies almost entirely on decoy traps, although other techniques may be used later in the project.
Achievements to date

1. Demonstration of the effectiveness of decoy traps in Denis Island’s habitats (and of the poorer performance of funnel traps, mist nets and ground nooses).
2. In the first two and a half months of the project over 500 mynas have been caught, out of a population estimated at about 1000 birds before trapping began (Jildou van der Woude).
3. Discovery that when groups of traps are placed together, catch rate among traps is variable. Experimental manipulation showed this not due to trap location or possible variation in trap structure or operation, but was due to presence of a specific decoy myna. Elucidation of what constitutes a “super-attractive” myna could improve trapping success.
4. Discovery that iris colour changes as juveniles mature, and that it is variable in adult mynas. Whether this variation represents continuing maturity, and is therefore related to age, or whether it is part of an annual cycle, or reflects mood of an individual, is unknown. Data are being recorded routinely among other features of all mynas caught. If a relation is found between iris colour and attractiveness as defined in section 3 above, this could be a pointer towards selecting attractive decoys.
Throughout May, at the beginning of the eradication, adult mynas were in wing moult, indicating that they were not breeding. In June wing moult was completed and breeding began. This was accompanied by a reduction in the rate at which birds were caught in decoy traps. A number of possibilities could explain this: requirement for different foods by nesting birds, reduced attraction to decoys and traps due to over-use of the decoys and lack of trap maintenance and cleaning, and reduced motivation of the trapper. Decoys were replaced with new birds and traps were overhauled, leading to a recovery in trapping rate. It appears that food choice of the birds did not change and that reduced motivation of the trapper led to lack of attention to the detail of trapping.
6. Comparative failure of funnel traps due largely to occupation of these by turtle doves (especially where food concentrations occur – see below) and crabs, mainly hermit crabs, when traps placed near the beach crest. Denis Island’s populations of Madagascar turtle doves, and also moorhens and mynas, are very high, indicating that the island provides abundant sources of food for them. The main food source concentrations identified are the pig farm, the food store on the northern coast, and the food offered to birds in the garden at the restaurant. Limitation of these food sources to birds would help to reduce the bird populations and would also help to reduce food wastage and its costs.
Lessons learned
We have within two and a half months removed almost half of Denis Island’s population of mynas and have additionally learned much new information about mynas and their behaviour in relation to trapping, including some insights into improvements that may be made. This success suggests that a major reduction in myna numbers on the island is feasible and that eradication should not be ruled out as a possibility and should remain the long-term goal. Decoy trapping is likely to remain the main tool but other techniques may need to be employed as numbers decline, with shooting at the nest being particularly important in the later stages.

Sooty tern project

2010-08-10T00:37:00.000-07:00

Previously, sooty terns Onychoprion fuscatus(formerly Sterna fuscata) nested on several island in the Seychelles group but on most islands, especially the smaller ones, colonies became extinct as a result of excessive egg and adult harvesting by people, introduction of exotic predators, and alteration of the habitat Following the successful eradication of rodents and felines early in 2000, Denis island proved to be an ideal site for such re-introduction as these characteristics coupled with food availability and proximity to the supplies proved key aspects that will cater for possible settlement. In addition, an area of ~2ha of open ground with attractant stimuli is available to encourage sooty terns to nest.

As part of Denis Island’s conservation effort, a sooty tern re-colonization programme was initiated in 2008, under the supervision of Professor Chris Feare. Sooties started to arrive on Denis early in June. The ‘wide-awake’ calls could be heard from the lighthouse area, all the way to the dive centre and the sooty tern area. For the month of June, every day was exciting as the situation with the sooty terns was unpredictable. There were days when hundreds of sooties flew over the island, to and fro in search of the ideal landing site and times when several birds landed for minutes and even hours. In the week of June, the island was a marvel to look at; high above in the sky as the colony moved from one end of the island to the next. There was one occasion where hundreds of sooties landed for hours, while some flew around trying to locate the perfect spot on the ground (see photo in side bar).

Friday 2nd July was particularly special to a lot of us who were present on the island. Though it was a rainy morning, there was excitement on the beach in front of the dive centre. More than 300 sooty terns landed on that beach, from the tip in front of the restaurant, right to the high water mark in front of the dive centre. It was unbelievable; having volunteers constantly monitoring their behaviour and movement at the designated area when the birds chose a different spot was quite disheartening for them. Helena and I were very lucky to be at the right place at the right time (See videos below and photos in side bar). It was amazing just to stand and admire those birds which not much is known of their migratory routes and behaviour post nesting season. Since then, the numbers have reduced considerably, with a handful being observed flying around every now and then.

Click on links below for footage of the sooty terns on the beach:

http://www.youtube.com/watch?v=gDJ90OLw1HI

http://www.youtube.com/watch?v=Yrm0yepNK6U

http://www.youtube.com/watch?v=R1TH6Gy8En4

Coastal zone workshop on Denis Island

2010-07-09T21:52:00.000-07:00

As part of the ReCoMaP’s funded coastal zone project, a stakeholder workshop was carried out in the first week of May on Denis Island. The main aim of the workshop was to introduce the stakeholders of Denis Island to the ReCoMaP project and Integrated Coastal Zone Management (ICZM) processes The setting up of the beach profiling points and the turtle monitoring protocol as well as training on beach profiling methods, turtle identification and tagging were the key workshop outputs.. After the initial stakeholder consultations on Denis Island in April, GIF staff also included presentations on coastal erosion and turtle monitoring. Concerns on these aspects of the island were raised during the initial stakeholder consultations. A steering committee was set up as well on the island to ensure that the project is being implemented and at the same time promote conservation initiatives within the island community.

The potential steering committee members had already been shortlisted previously on Mahe with following discussions with the Managing Director of the Denis Island Development Pty Ltd. This was the more realistic approach to use when staff movement, shifts and the island’s everyday operations are taken into consideration. A large number of the proposed members included front office staff because they are generally the first point of contact with visitors of Denis Island and it was found that the selected members were very keen to participate in the project. A list of equipment which includes a desktop computer, turtle tags and an applicator, GPS, beach profiling poles and an abney level were given to the chairperson of the steering committee to assist in the monitoring of the key coastal indicators.

The first part of the workshop involved the various presentations on the key coastal indicators of the island, which pertain mostly to coastal dynamics and biodiversity. Great levels of interests were generated from the participants, following the theoretical aspects of the training. The level of enthusiasm for the field survey surely surpassed our expectation. The photos on the side bar illustrate this clearly. Setting up the beach profiling reference points: The project team decided to use the standard Seychelles beach profiling method that was officially launched in July 2003. The method was developed by Dr. Gillian Chambers and is simple and easy to use. GIF adopted this method so as to enable data comparison between islands as this method is the Seychelles’ standard. The GPS reference of each point was also recorded.

At the end of the workshop and during the island visit, the monitoring stations for the beach profiles were established (see map above), the first data set was collated and a group of keen volunteers was identified to partake in data collection.

Figure 1:Map of Denis Island with the location and number of the reference points for the beach profiling monitoring exercise and the 6 different turtle monitoring sections.

For more information on the workshop for the Grand Anse Praslin site, do check the Green Islands Foundation blog on:

http://www.greenislandsfoundation.blogspot.com/

ReCoMaP project

2010-06-17T04:06:00.001-07:00

The last three months have been very interesting with project implementation for the GIF team, on both Grand Anse Praslin and Denis Island. The project in question is related to integrated coastal zone management (ICZM), funded by the European Union under the Regional Coastal Management Programme (ReCoMaP).

Entitled “Modelling coastal zone management scenarios in Seychelles using Denis Island and Grand Anse Praslin as pilot sites” this project aims to.address the management issues and user conflicts so as to develop Integrated Coastal Zone Management (ICZM) models and technical tools for application on other coasts of Seychelles.

Initiation of this project has been interesting as it allows us to work very closely with local communities dealing with several coastal zone issues, which range from sand movement, coastal hydrodynamics, beach cast and turtle nesting grounds. One of the key aspects of this project which was greatly considered in stakeholder workshops (See next post) is the identification of key community members to form the steering committee at each pilot site. The steering committee will assist greatly in the project implementation, namely in data collection which in the end, will provide the tools to develop an ICZM model and its functioning mechanism at the end of the project. This essential tool will provide the management framework that ensures stakeholders’ operations, meet government policy objectives and at the same time respect the rights of other stakeholders in the community. In the end, it will also provide guidance on environmentally-friendly operations.
There is also a wide array of overarching national stakeholders, namely Ministry of National Development (GIS Unit), Ministry of Environment Natural Resources and Transport (Environmental Engineering and Wetlands Section) and the Planning Authority. At the end of the project, we hope that such key model developed will be adopted at national level, in order to better understand and hopefully manage our coastal zone and its abundant resources.

Please click on the link below to read the full Newspaper article produced prior to the stakeholder workshop for each site:

www.nation.sc/index.php?art=19332

GIF Staff and work progress

2010-06-12T00:23:00.000-07:00

It has been a while since you last read our blog-a lot has happened in terms of project initiation and ongoing activities. I thought it is high time to spare a few hours just to put thoughts on paper so as to share our experiences of the past few months. Several; exciting activities and projects have kick-started and hence, I have not had the time to put everything in writing. I apologise for the delay and I do hope that you will enjoy reading this update.

Following the submission of the first blog by a new person for the year 2010, I find it necessary to introduce myself as well as the other new staff of Green Islands Foundation (GIF). My name is Michelle Etienne and I am the new General Manager of Green Islands Foundation. I graduated from James Cook University in Townsville, Australia with a BSc in Marine Biology and aquaculture. My childhood dream of working within the marine realm came true indeed, and coupled with my work experience from the marine research section of the Marine Parks Authority, I felt equipped with the necessary tools to take up this post. One thing which drew me to GIF is the fact that I am tackling conservation biology and management from a different perspective that is on islands which have made great initial progress in conservation on both national and international fronts. Moreover, these islands have so much to offer in terms of potential research and conservation initiatives. My background is mostly concentrated on marine conservation biology and also broad coastal zone management research. With this job, I am hoping to share my knowledge at the same time enhancing it, to gain maximum in all aspects pertaining to the natural environment of Seychelles.

GIF has also welcomed its Project Manager Mrs. Helena Francourt in March, to assist in the implementation of various projects, notably the newly initiated ReCoMaP project, which started in the 2nd week of March on the Island of Praslin, one of the pilot project sites.
This is what Helena has to say about herself:
“From a very early age I felt drawn to the music of the oceans that surround the Seychelles islands. This is not hard to imagine as I am sure many who have visited the Seychelles Islands will understand. For those who haven’t, our islands are characterised by turquoise waters, golden strands, striking reefs which are bursting with life of all shapes and sizes and all colours of the rainbow. It is particularly the reefs that drew me to explore the marine world. The Seychelles’ reefs are where the coral gardens absorb the intense light from our tropical sun, and the most striking of colours and combinations burst out and are revealed. It is always a gobsmacking experience to dive in the Seychelles.
By the age of 12, I was adamant that I would pursue a career in marine conservation. I started diving as soon as I was old enough to do so and by 18 years of age I was a qualified PADI dive master, working in dive centres during the school holidays. As a student I was also a very active environmental campaigner, participating in many environmental activities such as nature trail clearing, essay writing and public speaking competitions and so on. In the year 2000 my environment club won the prize of all environment club’s dreams; a trip to Aldabra! I am also therefore, one of the very few Seychellois and people of the world in fact who have had the opportunity to visit and dive on this atoll. It is in fact the most beautiful place I have ever visited and the experience is etched within me.
Not long after this life changing experience, I was off to Australia to study Marine Biology! No surprises there! I aced my way through my university exams and was accepted into the Marine Biology Advanced Programme which is designed to mould students for independent research and honors year. Upon my return to the beautiful Seychelles, I worked as a research officer at the Seychelles Centre for Marine Research and Technology (SCMRT) in the Marine Parks Authority. The experience I gained there was very fulfilling. To further diversify and gain different experiences, something which is very important to do here in the Seychelles, I moved to the Green Islands Foundation (GIF) this year (2010). I believe that this will provide endless opportunities to grow and learn about other aspects of conservation other than marine. These include endemic bird introductions and habitat restoration to name a few. I look forward to the challenges that lie ahead and I am ready to tackle them head on!”

GIF also has an environmental officer, namely Mr. Phil Greenwell working on Denis island, our key project site where we conduct numerous projects, such as the coastal zone management. Phil joined us in April to oversee the magpie robin programme and at the same time getting geared up for Professor Chris Feare’s visit for the sooty tern season and the mynah eradication projects. The two projects started in mid-May. (More details on these projects will be provided in the next post). Phill is based on Denis Island working on a variety of conservation projects. His main responsibilities are myna bird control; feeding & monitoring of the endangered Seychelles Magpie Robin and turtle monitoring.

Since graduating from Reading University in 2009 with his MSc in Wildlife Management & Conservation Phill has lectured BSc students in Animal Management before undertaking his current role with G.I.F. With extensive experience in captive animal management Phill has also gained conservation experience with the Wildfowl & Wetlands Trust in South Wales and the Department of Conservation & Land Management in Western Australia. Avian behavior and management are his main areas of interest, with academic work looking at invasive species (Rainbow lorikeet in Western Australia); preening behavior (inhibitory role of uropygial oil on feather bacteria) and impacts of wild bird trade on conservation. Born and raised in Wales, Phill has travelled widely for work, volunteer, pleasure and education purposes.

The months of March and April were mostly to initiate the ICZM project sponsored by the EU through the ReCoMaP, on both Denis Island and the Grand Anse- Amitie coast of Praslin, two key representative areas of ICZM scenarios in the country (see newspaper article in next post). A list of equipment was purchased to facilitate project implementation, notably in identifying and monitoring of key indicators on each site. Stakeholder analysis and consultations were carried out to assist in the key indicator identification that is, finding the key issues that seem problematic to the local community. A stakeholder workshop was organised at each pilot site with the aim of disseminating information about integrated coastal zone management and also provide training to the residents on the ways to monitor their key indicators, notably turtle monitoring and beach profiling (See photos in side bar).

In May, Denis Island welcomed Professor Chris Feare, who arrived for this year’s sooty tern re-colonisation project as well as to initiate the mynah eradication programme.The first Sooty Tern to be recorded over the ‘sooty tern area’ in 2010 was seen on 1st June, and on 3rd June the first landing was observed. In the mornings and afternoons Sooty terns are now seen frequently over the area and several birds have landed for short or longer periods (one for 40 minutes) (Feare, 2010). There is photographic evidence that mynah birds are major nest predators and competitors to a lot of birds on the island, notably the introduced endemics such as the Seychelles magpie robin and the paradise flycatcher. As a means of control of this invasive alien species on the island, it was necessary to initiate such a programme (See next post).

The last three months have been busy with project initiation and ongoing projects, which have been positive in their outcomes. So far I can say that the GIF team have learnt a lot and seen a whole lot of things from a different perspective.

My first Denis Island Experience

2010-03-15T21:47:00.000-07:00

Sunday 21st February was a very interesting day for me- I got to visit Denis Island for the first time! I did not know what to expect as I’ve read so much the island and liking it instantaneously, without really knowing it! As the plane hovered over the island, I sat in awe as I stared down at the crystal clear waters and the array of greens, clearly visible from high above. The first sight of the island surely impressed me. Once the plane landed, I was met by a number of the island staff, from both the hotel and the estate; at that point in time, I knew that there will be lots to do and learn around the island! I was then introduced to Mr. Camille Hoareau who was going to show me around the island to provide me with a good insight of the ‘real thing’ in situ.

After the plane left, it was back to usual business for everyone. I was driven to the staff canteen to enjoy a nice Sunday lunch before checking out my accommodation and doing the island tour. Seeing the mix of staff of the island was interesting- my presence arose some curiosity but before lunch was over, I have talked to several staff and got their perspectives of the island and its biodiversity. My first impression of the island was one of absolute awe; peaceful surrounding with various bird species flying around, perfect sunny weather giving a nice aura to the grass, while the waves slowly splash on the beautiful sandy beaches. With these characters showing off to me, I knew then and there that the island has a lot to offer and its biodiversity is simply amazing, hence worth preserving!

The tour of the island was done in a golf car with Mr. Hoareau as the driver and my camera in focus, to try and capture the best shots as we drove along and stopped at the various sites of interests. Some of the most fascinating things I saw was a Seychelles warbler and a Seychelles magpie robin (Copsychus sechellarum) (photo in side bar) coming quite close to the golf car, following Mr.Hoareau’s call. Driving past and through the woodland forest, I saw the feeding stations of the SMR empty, even if food had just been placed. However, not one of the birds was in sight. The native woodland forest is evergreen and rich of life (picture in side bar); constant bird calls resonating from its every corner are simply amazing. Moving on, I got the chance to see the ongoing rehabilitation area, where young coconut seedlings are pulled out- the shoots are mashed up to provide fodder for the livestock on the estate. Papaya grows in great abundance all around the island and it is amazing to see the size of the fruits on those thin trees. Even if they are found within the woodland boundary and other prime land, the fruits are also used as food source for humans and the livestock. Nothing is wasted really- accumulated seaweeds during the monsoons are placed in a big stack to allow rinsing when it rain and decomposition into more ‘friendly’ materials to be used as compost on the vegetable garden.
Other problematic invasive species are removed from the forest in order to allow young native seedlings to proliferate. This activity is laborious but it is worth mentioning that the estate staff with the help of the management staff is determined to keep it going- well done guys! Lots of effort and investment are being put in the restoration and maintenance of near-natural habitats. This is an ongoing and never-ending venture which must be applauded and further encouraged, to allow continuity and eventually engage other islands to follow suit.

Sometimes we don’t really understand how Nature works! Driving along the coastline, I noticed that there are serious erosion issues, leading to loss of beach materials and vegetation, including beautiful but enormous casuarina trees- a real shame!! There are plans to mitigate some of the vegetation loss and beach erosion, once the ICZM project, funded by the ReCoMaP kick-start. It will not be the answer to this problem, but it will provide a certain degree of coastline protection in the long run. New and large beaches have been formed and large amounts of materials have been transported all along the coastline. This in turn leads to ‘suffocation’ and displacement of coastal vegetation as the plants are fully exposed to other natural elements and the open sea. Large trees such as casuarina that have been resident on the coast are now disappearing at very fast rate, thus raising alarm on the urgency for mitigative measures to be put in place.

Driving past, I noticed a very distinct spot at Bel Etoile beach where the coastal features have molded the reef flat into wonderful architecture; the sight was indeed mesmerizing. This site was very popular for wedding ceremonies but with time, the system has disintegrated with prolong wave erosive actions. Such loss really prompts the urgent need to act now, so as to, if possible, lessen such impact on other coastal features.

As the sun went down, I stood in total amazement as myriads of birds came to settle on their favorite branches and trees for the night. I made a new friend, a fairy tern which was curious to observe what I was doing with the camera. I tried to take its photo but it was too busy playing and in the end, I chose to admire them all! Once darkness settled in, I made my way to settle for the night.

The next morning, I decided to have an early morning walk with my camera with the idea of capturing some other good shots. Everywhere was quiet and there was not much action; I diverted to the kitchen for breakfast as it was uneventful. I encountered a brown noddy chick taking its time to get around. It was friendly as it proudly stood to pose for me (photo on side bar) and I was happy to get my first photo for the day. As the sun rose higher up, it started to get very hot and wandering around the island for photos mid-morning was becoming quite a task. By then it was also time to get my bag ready for my return trip back to Mahé, so I headed back to the house.

It had been a very interesting first trip which have impressed me a lot and giving me the feeling to return as soon as possible. It was amazing to see what lies within the trees and branches of Denis Island and to have a good insight as well as the element of surprise as to what will be waiting for me when I return soon, to get started on the coastal zone project!

Paradise Flycatcher Conservation Project – breaking news…

2009-10-21T21:57:00.000-07:00

Rachel Bristol (Project Officer under the Seychelles Paradise Flycatcher project) visited Denis last week to catch up on the Flycatcher population there and their status. On her return she was able to report some excellent progress including the commencement of breeding activities for the new season and some early successes, Rachel Continues below:

“After a few months break the flycatchers on Denis have started breeding in force again. Flycatchers can breed year–round but there is a marked peak in breeding during the North-West or rainy season from November- April. However, the dry South-East season this year has been considerably wetter than usual which likely explains the early start to the breeding season.

I was on Denis last week and of 8 potentially breeding pairs six of them are currently active. We have 2 new fledglings that fledged two weeks ago and yesterday (19 October 09) respectively, a nestling just hatched yesterday and 2 further pairs are nest building. A 6th pair has a dependant juvenile that fledged in August.

Now almost 11 months since the Conservation Introduction of 23 flycatchers to Denis we are beginning to get an idea of how successful the introduction will be. The current population is 24 individuals; we have lost 4 of the original introduced stock but have had 5 chicks fledge on Denis. After a shaky start where the majority of nesting attempts were failing (due to a combination of eggs failing to hatch and de-predation of both eggs and nestlings- [ed: most likely by Mynah Birds a problem which still requires redress]) the flycatchers appear to be “getting it together” and successfully breeding on Denis- the key to establishment of a self-sustaining population.”

This really is fantastic news – the Flycatcher transfer to Denis in November of last year was the first ever transfer of this critically endangered species and constitutes a key step in securing the future of this beautiful and iconic endemic species.

This success is largely down to the tireless efforts of Rachel over the previous three years. Rachel is currently working to complete her PhD thesis on the species and we wish her all the best in her ongoing endeavours.

While she was on Denis Rachel took the opportunity to measure and ring a flycatcher nestling and has kindly sent us some great photos of the young bird see photos in sidebar.

The Seychelles Paradise Flycatcher Project is a multi-partner undertaking funded by the Darwin Initiative and supported by partners including Nature Seychelles, the University of Kent, the La Digue Development Board, Denis Island and the DoE.

All creatures great and small…

2009-10-02T00:26:00.000-07:00

It has indeed been a considerable time since I last visited Denis as a confluence of events and paperwork deadlines have kept me “trapped” on the main island of Mahe. This has in turn meant a marked decrease in my posts from an average of 8 posts a month through July to just 2 and 1 in August and September respectively.

This, by chance, has meant that visitors to the blog of late have been greeted upfront by photos of the Seychelles skink and a couple of species of crab – perhaps not everyone’s cup of tea or idealised perception of an idyllic tropical island. At this point it is timely for me to state that Denis is very much the epitome of a picture postcard tropical island and I am certain will meet the requirements of such from its visitors.

The spectre of brown lizards and hairy-legged crabs has however been visited upon me today by a member of the island’s marketing section concerned that the perception generated is inappropriate. Perception is of course - in these modern times of multi-media, sound bites, 24-hour news and spin-laden politics - increasingly everything with substance coming often at best second.

Lizards and crabs play a vital role in the island’s ecosystem breaking down detritus and recycling nutrients. It is imperative in the management of fragile islands that a comprehensive ecosystem approach to environment is utilised and that all native species, regardless of aesthetic appeal, are incorporated therein. Without one there is often not the other as each contributes to the health of the whole.

However, visitors to this blog and prospective visitors to Denis Island can rest assured that they will find yearnings for both perception and substance satisfied in the environmental management of the island. That is not to say all is perfect, the rehabilitation and restoration of the island’s ecosystem is a long term process but great steps have been made.

The key alien predators, cats and rats, were removed in 2000 and 2002 respectively. This coupled with extensive habitat rehabilitation paved the way for the introduction of rare and threatened species such as the Seychelles warbler, Seychelles fody, the endangered Seychelles magpie-robin and the first ever transfer of the critically endangered Seychelles paradise flycatcher.

Thankfully from a marketing perspective these birds are also pretty… see photos in sidebar.

Meanwhile the work continues on all creatures great and small.

The Seychelles Skink (Mabuya sechellensis)

2009-09-02T23:21:00.000-07:00

A common sight on the ground in the woodlands of Denis, and indeed throughout the central Seychelles archipelago is the Seychelles skink (Mabuya sechellensis). This species is endemic to the central Seychelles.

On Denis this coppery-brown lizard gets up to approximately 22-23cm in length – including its tail. It has a distinct pale stripe running from above the eye down the top of each flank fading out at the tail. This stripe is emphasised by rows of darker patches running above and below it (see photos). This pale stripe and the pale belly in turn make the flanks appear as a brown stripe. The striping varies in prominence from island to island with adults in some populations reportedly not having stripes.

On some islands the skink can reach very high densities (e.g. Cousin) but this is not the case here. On Denis one generally first notices a skink by a rustle in the undergrowth as it seeks to avoid our great marauding feet! The best way to observe them I have found is by moving off the paths into areas of broadleaved woodland and just finding a comfortable perch. Once still, one rapidly becomes aware of the movement of the skinks across the forest floor and they often approach as curiosity brings them in search of food.

Gerlach (2007) states that the skink has been introduced to Denis and some credence is provided to this idea by the fact that no skinks were recorded on Denis’ nearest neighbour Bird in 1908 (Fryer 1910) but were subsequently found in 1939 – a timeframe highly suggestive of a human vector. For Denis though it is not so conclusive. Skinks were recorded in 1908 and it is definitely possible that they could have arrived on Denis during its 14,000 year history through natural means – i.e. “rafting” on floating vegetation.

Regardless the skink, as a species endemic to the central archipelago, is treated as native species and serves an important role in the ecosystem feeding omnivorously on insects, fruit, detritus and carrion. Skinks also provide a source of food for moorhens and interestingly the endangered magpie-robin which is highly adept at swooping down on an unsuspecting young lizard and despatching it clinically by 2 or 3 hard “thwacks” against a stone before consuming it.

The skinks lay 2 or more oblong, leathery white eggs and cover them with soil. We do anticipate that as sea bird colonies increase on the island that the detritus they bring – small fish, droppings, eggs and dead birds – will see a corresponding increase in the skink population.

Refs:
Fryer, J.C.F. (1910). Bird and Denis Islands, Seychelles. Trans. Linn. Soc. Land. (2)14: 15-20.
Gerlach, J. (2007). Terrestrial and Freshwater Vertebrates of the Seychelles Islands. Backhuys Publishers. The Netherlands.

Catching-up…

2009-08-28T04:41:00.000-07:00

Leave and then the frantic writing of a project proposal to meet the donor deadline have kept me from posting for nearly a month and away from the island for longer, so just a few quick bullets to bring the blog up to date:

Great news from Rachel, we have now our third successful fledging of a Seychelles paradise flycatcher on the island which is most encouraging. Breeding activity has now ceased as is usual for this time of year.
Vicki and Georgia headed home at the end of July. Their work on the Sooty tern project was very fruitful with numerous landings recorded and very encouraging behaviour displayed. We believe that the birds that visited the island this year are young adults that have not previously bred reconnoitring potential breeding sites for the future. If so this is indeed a very encouraging development. I look forward to receiving the write-ups of their work and also hopefully they will contribute a post or two to the blog.
Jildou and Peter have finished their work on the warblers (Acrocephalus sechellensis) on Denis for this visit and dropped by to the office last week to update me on their findings. They were able to catch and ring 99 birds during their stay and estimate that the island population is about 150 - 175 birds. There are now approximately 75 territories on the island. Once independent, young birds leave their natal territories. There are therefore a certain number of birds “floating”. That is to say moving round the island looking for a territory of their own. On Cousin Island where the warbler population is at carrying capacity the birds exhibit cooperative breeding where the young, and particularly the females, often remain in their natal territory and help their parents raise the next generation of siblings. This different life tactic is utilised because the entire existing habitat is occupied and the bird’s evolutionary fitness is optimised by helping to raise its siblings and seeking over time to either inherit the territory or gradually establish a territory off the side of the existing one. The high proportion of unringed birds found in the population during this visit is evidence of ample successful breeding but also suggests a quite high rate of adult mortality. Of particular concern is that Jildou and Peter estimate that 1 in 5 of the adults shows evidence of scarring and injury around the head. Such injuries are not evident on the other island populations and once again suspicion points to the predatory impact of the invasive Mynah bird.

I don’t know when I will be going back to the island, but I do have a backlog of a few things I could post on so I will try and post a couple of times over the next week. Keep checking back for updates…

More on littoral crabs... new records for Denis Island.

2009-08-03T06:55:00.000-07:00

I posted at length on the 5th of July on the Sally lightfoot crab (Grapsus tenuicrustatus) and was able to get a few good shots of the animals as waves broke over them. G. tenuicrustatus is a common sight on the sandstone formations to be found around the southern and eastern coastline of the island and is indeed the only rocky shore crab previous studies have recorded on the island. I was very interested therefore to find other species present in the southern rocks when I was trying to get photos of G. tenuicrustatus. They were much more shy than the “Lightfoots” and difficult to photo but I was able to get a few snaps sufficient for their identification.

Eriphia smithi – rough red-eyed crab, red-eyed reef crab, pebble crab

E. smithi has an indo-pacific distribution and is reportedly very common on east African coasts. It has various distinctive characteristics which when combined allow for species identification. Most apparent are the bright red eyes on white stalks and this immediately narrows down its identity, this coupled with the numerous spines on carapace edge behind the eyes and the large molariform tooth on the larger claw clearly identify it as E. smithi.

This is an interesting species that grazes on algae during the day but turns predator of crustaceans and molluscs at night. At low tide at night individuals have been reported to roam out up to 50m on to reef flats in search of prey before returning to their crevice hideouts (Vaninni et al 1989). Rock crevices play an important part in their lifecycle for seclusion and mating and individual crabs can remain loyal to a single retreat for 3 weeks or more. The southern reaches of the island seem ideal in this regard with numerous cracks and crevices in the sandstone and large reef flats that are exposed at low tide.

Geograpsus stormi – red nipper.

Now I can’t be sure of this identification as I do not yet have a full dorsal photo of this crab (it moved very rapidly and agilely over the rocks in its search of refuge) but judging from the colour of its legs and eyes and the presence of prominent long bristles on the legs I am fairly certain that it is a specimen of the rocky shore crab G. stormi .

G. stormi has a western Indian ocean to central pacific distribution (Richmond 1997) and has been noted for its consumption of rocky shore carrion. Interestingly Haig (1984) records G. stormi as only occurring on islands that fit the habitat category of “low islands with mangroves” - in this case citing the outer island atolls of Aldabra and Cosmoledo. She does however go on to note that it is likely that G. stormi (inter alia) will be found on islands without mangroves as more “collecting” is done.

References:
1). Cook Islands biodiversity Database (2009). http://cookislands.bishopmuseum.org/species.asp?id=7351
2). Haig, J. (1984). Land and freshwater crabs of the Seychelles and neighbouring islands. In: Stoddardt, D.R. Biogeography and ecology of the Seychelles islands. Junk Publishers, The Hague.
3). Richmond, M.D. (1997). A guide to the seashores of Eastern Africa and the Western Indian Ocean Islands. ISBN 91-630-4594-X.
4).Vaninni, M. et al (1989). Feeding habits of the pebble crab Erithia smithi. Marine Biology 100, (249 -252) 1989.

Nature Notes & Bird Bulletin…

2009-07-24T22:42:00.000-07:00

I am taking some leave in the coming weeks so posts will likely be scarce for a good few weeks. I will use this combined “Nature Notes & Bird Bulletin” post to summarise a few odds and ends from my last island visit.

Nature Notes

Magpie Robin News. We have experienced some considerable set-backs in recent months with several chicks lost to Mynah bird attacks and two adults lost to illness. This is a matter of real concern as the population has decreased to 20 birds which is the number we started with a year ago and we have lost more females than males from the adult population. It is urgent that we take measures to improve breeding success in the population. The estate has been assisting with localised habitat management creating higher quality feeding grounds in each territory. Meanwhile I am in final negotiations with the island under what conditions we can bring a marksman to the island to undertake a preliminary cull of the Indian mynah population. The Indian mynah (Acridotheres tristis) is an invasive alien species in Seychelles and a highly effective predator of the eggs and chicks of our rare endemic species – so we have to deal with it. On a positive note I encountered a family group of three birds on the path called “L’Allee Bodamye” I was walking from the central path junction in the island when I noticed a single SMR following me. I took the opportunity disturb the leaf litter with my feet in order expose the insects upon which the bird feeds and moved on. When I looked back there were three birds on the patch of scraped ground. Such a sight even today is significant as it represents approximately a 60th of the world’s entire population of this endangered species. So I turned to take a few photos. One of the adults on seeing that I had stopped however soon came forward making its “churring” aggressive call. So not wanting to stress the birds I cleared another patch of leaves and left them to their foraging.

L’Allee Sed. The path that leads from the west coastal path to the island’s main central junction (mentioned above) is called “L’Allee Sed” because it is formed by an avenue of casuarina trees. L’Allee Sed is one of the older features on the islands. Casuarina trees were likely planted on the island from the 1860s onwards to provide a better windbreak for the coconut plantations and I have found reference from 1907 to the stands on the island being a major feature. The L’Allee Sed is therefore recognised under the island’s management plan as an important historical and ecotourism feature of the island that needs to be maintained.

Sally lightfoot crabs. In my post of 5th July I wrote about this species of crab and its special adaptations to life in the breaking waves. I also mentioned that on occasion the cast off exoskeletons could sometimes be found. During my last trip I indeed find one on the southern rocks see photo in sidebar.

Bird Bulletin

I am pleased to report that both Paradise flycatcher fledglings are alive and well. Rachel Bristol, the Flycatcher Project Officer, is currently out on the island to follow up on the population so I should have more detailed news soon.
Sadly the ground-nesting Tropicbird to the south of the island that fledged its first chick in December appears to have abandoned its nest without breeding this time – there are few factors that may be involved and I will follow up on the site closely.
I noted only 1 Crested tern on the island last weekend interesting as I had recorded my highest ever count of 15 only a few weeks ago (see Post of 8th June).
Sooty terns are a common sight and sound overflying the island aside from the actual project area they are particularly notable displaying over the northwest coast at Pte Mme Guichard.
I checked on the White tern chick, the rescue of which I reported on in my second post of 5th July and am happy to report that it is growing well see photo in sidebar.

Studying the Seychelles warbler population on Denis…

2009-07-22T22:41:00.000-07:00

As mentioned in my post of 8th June arrangements had been made for some researchers from Groningen University in the Netherlands to come to Denis to undertake a study of the Seychelles warbler (Acrocephalus sechellensis). The Seychelles warbler was introduced to Denis in 2004 as part of its ongoing national conservation plan (see post of 08/06 for more info).

The researchers Jildou and Peter arrived three weeks ago and were straight into their work. The establishment of a new population on an island offers plenty of scope for research. Jildou and Peter will be investigating the warbler’s population growth since 2007 and undertaking a detailed survey to ascertain survival and reproductive success in the population. Jildou and Peter are working under the supervision of Dr Jan Komdeur who worked in Seychelles for several years in the late 1980’s and early 1990’s. Jan was the man responsible for the propagation of the warbler to other islands that has done so much to enhance the conservation status of this endemic species. His detailed research of the warbler and its habitat requirements enabled the transfer of birds from the then sole colony on Cousin island to the islands of Aride and Cousine and latterly Denis.

Jildou and Peter are looking in particular at female mortality. There is evidence from the previous Denis survey in 2007 that the warbler population was skewed, with more males than females. Birds on a new island with abundant vacant habitat undergo more rapid reproduction than they do in established populations simply because resources are more abundant. Breeding is an energy intensive activity particularly for the females. It is postulated that this investment by the females may detract from their longevity and hence the development of a skewed sex ratio in the population.

Jildou and Peter will therefore be monitoring levels of stress in the birds by taking blood samples and checking for levels of oxidative stress, they will also be looking at the level of stress hormones in warbler faecal samples. They are furthermore looking at the levels of immunocompetence in the birds by assessing a variety of physical characteristics of the birds – as stress can affect immunocompetence.

This research is very interesting and has various ramifications for the planning of bird translocations in the future. From a Denis viewpoint, we are particularly interested in an update on the status of the population, its distribution and habitat use as this will help inform decision-making with regard to vegetation management on the island.

Keep checking back for more updates on Jildou and Peter’s endeavours.

Sooty tern update…

2009-07-22T01:13:00.000-07:00

Part of the island’s management plan is in effect about turning back the clock. The southern portion of the island has been identified for restoration. The long term goal is to take this area back, as close as we can, to its original state when first discovered by man. De Trobriand the discoverer of Denis in 1773 left us a fascinating and quite detailed description of the island and its wildlife.

One of the dominant seabird species found on Denis at that time was the Sooty Tern (Onychoprion fuscata). Today one of the first aspects of restoration we are broaching is an attempt to re-establish a breeding population of Sooty terns on the island. Whilst we do not have specific records on the history and fate of the original sooty tern colony, we can draw certain conclusions from the island’s known development history and it seems probable that the bird has not successfully bred on the island for some 150 years.

We are now into the second year of this project and as such work has never been previously undertaken with the Sooty tern we are breaking new ground and learning as we go along. In this second year we have refined our approach following the results of last year and it has definitely been more successful (Previous posts cover the earlier stages of the project see: 19/05/09 and 02/07, 21/09 & 13/10 2008).

The sooty tern project was the focus of much my attention during my last visit to the island and it was most encouraging. On the Thursday afternoon I observed a few birds circling and a couple on the ground but it was on the mornings of Friday and Saturday that things were much more interesting. GIF volunteers Vicki and Georgia have been working steadily on the project and I hope that one or both of them will post soon on their perspective on the project. Both of them were present on Friday morning and the project area was alive with activity. Up to 37 birds were to be seen on the ground at a time with many more circling low over the area and calling. The birds on the ground were observed courting and mating and interacting as if a colony was under formation – it was fascinating stuff. The occasional bird was still seen to attempt to mate with one of the models as well. The next morning was much the same with up to 35 birds being observed on the ground at any time this time with the birds in general occurring in a single group.

It is unlikely that we will see any egg-laying on the island this year as, despite the delay in the onset of the southeast monsoon, egg-laying commenced in the existing Sooty colony on Aride Island in early June. Nevertheless the results this year are much improved from last and we continue to learn more about the bird’s preferences and how we might better design the project next year. According to studies the Sooty tern does not return to breed until it is 6 or 7 years old so it may well be that the birds we are attracting are young adults that are reconnoitring potential breeding locations for next year – let’s hope they keep Denis in mind!!!

Southeast monsoon.

2009-07-20T00:00:00.000-07:00

Flying to Denis on Thursday 16th July it was clear that the southeast monsoon was blowing strongly and had finally, properly established. Seychelles has two seasons determined by the direction of the prevailing wind either the northwest trade winds or the southeast monsoon. The southeast monsoon has been very late establishing this year and this affects the habits of many animals notably the breeding activity of seabirds that rely on the seasonal winds and related currents to bring the small fish they need to breed and successfully raise a chick.

I hadn’t been to Denis for a couple of weeks and last time I was there the southeast was blowing intermittently. On Thursday the white caps of waves were visible throughout the flight from Mahe to Denis. As the plane descended and approached the island, choppy water was evident on the surrounding shoals and then I saw something that I have never previously seen. A plume of sand was being carried offshore from “Pte Mme Guichard” on the northwest point of the island, off the shoal and into deeper water.

I have been monitoring the cycles of sand movement on the northwest coast since December 2005 and there is definite evidence of erosion. The difficulty in assessing such changes however is the fact that there may well be ongoing long-term cycles of erosion and accretion for which we have no information. It is therefore not possible to see short term changes in coastal profile in the proper context. Such thoughts are further complicated by ongoing changes in global weather patterns and the related issue of sea level rise. It is important however to monitor trends in coastal erosion in particular on the shoreline where key infrastructure is located in order to inform management decisions.

On seeing this sand plume going offshore and into deeper water it occurred to me that such sand loss may be permanent. Normally when I fly into the island I have camera ready for in case of a good photo-opportunities but on this trip because of the cloudy weather and poor light I hadn’t bothered. So I had to scramble to get the camera and snap some shots… so not great but good enough to show the occurrence… see photos in sidebar.

There was further evidence of the onset and stabilisation of the wind on the island. The sand promontory at Pte Mme Guichard has been largely eroded – a usual part of the island’s beach profile dynamics. I had reported previously (see post of 8th May amongst others) about the recovery of vegetation a Belle Etoile on the east coast following the cessation of grazing cattle there. This had greatly changed the view of the area with the former open meadows and casuarina-framed vistas obscured by the dense growth and foliage of papaya thickets. Well the salt spray driven by the “southeast” wind has changed this dramatically the leaves are gone leaving the barren stems to point accusingly at the sky.

Another key issue related to the southeast monsoon is that it will also mean that the Sooty tern season should get properly underway… but that is the subject of another post…

Shells 2: The Minstrel Cowrie - Cypraea histrio

2009-07-13T03:00:00.000-07:00

On Tuesday the 18th of November I posted on the mollusc Trochus virgatus and now, having not been to the island for a couple of weeks, seems to be an appropriate time to continue that theme.

During November we had some good high tides and wave action that served to wash up quite a few dead shells from the surrounding reef flats. At the same time I found the T. virgatus I also found a good specimen of the Minstrel cowrie (Cypraea histrio). The pictures below show the specimen of this beautiful species of sea snail and can be enlarged simply by clicking on them.

Jarrett (2000) states that C. histrio is very common in Seychelles where it occurs in shallow waters and rarely deeper than 3 metres.

Ref: Jarrett, A.G. (2000). Marine Shells of the Seychelles. Carole Green Publishing, UK.

Day geckos (Phelsuma astriata and Phelsuma sundbergi)…

2009-07-09T01:34:00.000-07:00

Visitors to Denis will all notice the bright green geckos that can be seen on the trunks of coconut trees and at night on the columns in the restaurant – where they lie in wait by a light to capture the insects it attracts.

There are in fact two species of day gecko to be found on the island the Lesser day gecko (Phelsuma astriata) and the Day gecko (Phelsuma sundbergi). Both species are endemic to the granitic Seychelles but are believed to have both been introduced (presumably inadvertently) to Denis. Gerlach (2007) states that P. sunbergi was first recorded on Denis in 1908 whilst P. astriata was introduced as recently as 1981. Of course lizards can and are known to colonise distant islands via floating vegetation so such matters are never entirely clear cut but the apparent recent nature of these colonisations does very much suggest a human vector. Regardless both of these species are now well established on the island and as species endemic to the central archipelago are more than welcome.

P. sundbergi is the much larger and heavier set species (getting up to about 20cm long including its tail) when mature and tend to be territorial. Typically one will be evident per coconut trunk or column on a boat shed or verandah and when two occur they will often be seen to fight. They are particularly noticeable to visitors as it is this species that populates the columns around the restaurant. They are typically bright green with on closer inspection, a light red freckling on the back of some individuals.

P. striata is significantly smaller (10 -12 cm including tail) and much less sturdy in build than P. sunbergi and can be seen on vegetation, tree branches, palm leaves and also on walls. It has visible pale belly and interesting red patterning on the bright green of its back and head. The adult has a distinctive red chevron on its head typically followed by two transverse bars on its neck (see photo in sidebar – this specimen has dots rather than the bars but it was a juvenile and the bars may form later). They typically have a spinal red line with patterns of red dots. On Denis these dots often merge to form a herringbone pattern (see sidebar). Occasionally a black P. striata can be seen this colour change is a reversible defensive stress response.

The Palm Spider (Nephila inaurata)

2009-07-08T04:34:00.000-07:00

Arachnophobes need read this post no further – but of course do scroll down to other posts! - as this spider fits the bill as a pretty frightening beast if you are that way inclined.

The Palm spider (Nephila inaurata), also known as the “red-legged golden orb-web spider”, can get pretty big. I have seen them, including leg span, soup dish-sized and building their webs from the telephone lines to the ground in the south of the main island of Mahe!

They are fairly common throughout Seychelles and on Denis can typically be seen in their webs along forest paths. The spiders themselves are harmless – unless of course you are an insect – and during fieldwork I have often accidentally walked through a web and had a spider scrambling over me, generally doing the best it can to get off as quickly as possible.

Their webs are strong and are reputed to be able to ensnare even small birds though I have never observed such an occurrence. The large spider at the centre of the web is the female whereas the male is very much smaller and can often be seen nearby typically on the other side of the web (see photo in sidebar). I am often asked and do not have the answer for whether the female eats the males – I don’t think so – but it may be for good reason that the males are typically found on the other side of the web!

I have dithered as to whether to do a post on the palm spider for fear of putting off people from visiting the island. This however is the tropics and visitors to such destinations should expect to find life teaming in all forms. Seychelles in fact has very few creepy-crawlies when compared to tropical continental landmasses and none of them are dangerous. In the case of this spider it remains stationary in its webs in the forest and is not one that you need worry may come and visit you in your room. So don’t be put off, the Palm spider is in fact a very interesting species fulfilling its role and occupying its place in the island ecosystem.

White tern (Gygis alba) rescue

2009-07-05T22:00:00.000-07:00

The white tern (Gygis alba) is an unusual bird in several respects. In particular it does not build a nest but rather lays its egg in a hollow or fork of a branch. This requires some particular adaptations by the chick in particular the ability to anchor itself to the branch with its claws even before properly emerging from its shell. Chicks therefore have well-developed feet and claws whilst the rest of them is little more than a fluffy ball of feathers.

The strength of its claws was brought home to me a couple of weeks ago on the island whilst taking some tour operator representatives on a tour round the island. I was actually looking for a Seychelles warbler that I had just heard when I looked up to see a white tern chick hanging upside down from a branch. I initially thought the chick was dead but then I saw an adult sitting on the perch above and looked more closely at the chick. It was alive with breathing and eye movement evident and hanging by just a couple of claws of one foot… not a good situation.

The bird was a good 15 feet off the ground up a spindly ornamental tree near the main hotel complex. I went in search of a ladder and on my return, having with the assistance of some of the tour reps worked out how to properly extend it, still found the ladder too short for someone of my limited climbing capacity to reach the bird. Fortunately a young man from the garden staff was walking by and I asked him if he would be able to help. He took one rather dismissive look at the ladder, and proceeded to shin agilely up the tree retrieved the bird and replaced it on the perch where the adult had been!

I had been too preoccupied to get a photo of the chick whilst it hung precariously, but one of the tour reps, Amy Pearson, did get a shot of the rescue which she has kindly sent to me (see sidebar).

I went back the next week to check on the chick and found it well and on its perch - so a nice little feel-good story for all involved!

The “Sally Lightfoot” crab or Karkasay (Grapsus tenuicrustatus).

2009-07-05T06:58:00.000-07:00

I have previously posted on the importance of hermit crabs in the island ecosystem (see post of 16th July 2008) and the work we have undertaken to look at the occurrence and populations of the three species that occur on the island.

Denis, of course, has other crabs of both land and coastal species and in this post I will focus on the “Sally Lightfoot”, known locally as “Karkasay” (Grapsus tenuicrustatus) which is a crab of rocky shores. It is interesting that the species occurs at all on Denis as the island is a sand cay without rock. Denis was formed during the last glaciation when sand piled up on a patch reef that today forms the reef flats around the north, east and south east coast of the island and can be considered, in some respects, as the “backbone” of the island.

The “rocks” that are to be found around Denis and that form the habitat for G. tenuicrustatus are in fact made of sand! A large part of Denis’ surface area is today actually made up of sandstone. Sandstone that was formed from the action of acids, leached from millennia of sea-bird droppings, acting to bind the coral sand particles together. There are in fact two layers of sandstone on the on the island suggesting that it may have been submersed at some point in its history before re-emerging above the waves.

This sandstone is not particularly strong – it being possible to break fragments of it by hand – it does nevertheless form a solid structure against wave action and can be found forming extensive wave-smoothed tablets along the east, south and south west coasts of the island and distinct outcrops at the southern point of Denis. This therefore is what provides the habitat for a rocky shore crab on an otherwise sand cay island.

G. tenuicrustatus is a herbivore that grazes on the algae that grows on rocks on the coast. Its sleek highly streamlined form, necessary for it to cling to rocks as waves break, gives it an almost alien appearance when seen in profile. Research elsewhere (Martinez 2001) has shown that a very minor shift in stance of the crab greatly reduces its drag in water and enables it to withstand 200% faster flow of water without being dislodged.

The Karkasay on Denis are alert and wary of intrusion, very swiftly retreating into crevices or if necessary jumping into the sea when someone approaches. Clearly this is a predator avoidance technique and though I have yet to sea anything predate them I imagine visiting herons and the ever present conger eels pose a threat - not to mention of course man, seeing as Karkasay make a good curry!

I was able to get some good shots of the crabs on the south and southwest coast (see sidebar). Of particular interest was that the crabs did not retract their eyes at the moment a wave hit, further evidence of their adaptation to the coastal environment.

Sometimes what appears to be a pink-red corpse of a crab can be found intact on the rocks – this is in fact an exoskeleton shed by a growing crab.

There are several other species of crab to be found on Denis and I aim to cover them in future posts…

Ref: Martinez, M.M. (2001). Running in the surf: hydrodynamics of the shore crab Grapsus tenuicrustatus. Journal of Experimental Biology, 204, 3097-3212, (2001).

Focus on the Seychelles Turtle Dove (Streptopelia picturata rostrata/picturata)

2009-07-03T05:04:00.000-07:00

A lot has been written about the Seychelles turtle dove (S. p. rostrata) and its progressive demise by cross-breeding with the larger and introduced Madagascar turtle dove (S. p. picturata). Although there is no real consensus the general view is that Madagascar turtle dove was introduced probably as a released food supply by a calling vessel in the mid-19th century - though Beamish (1981) states that it was introduced as recently as the early 20th century.

The Madagascan race is larger than the endemic Seychelles race and males compete for access to mates. The males face off side to side and jump and bat their near wing on the ground in aggressive displays. Feathers puffed out, back arched and outer wing raised they attempt to intimidate their opponent by the impression of greater size. If this does not work, then fighting can ensue with the birds then hitting each other rather than the ground with their wings until supremacy is established. The advantage is clearly with the larger bird resulting in more successful breeding by the Madagascan males and the spread of their physical characteristics through the population.

Some authors go into great detail describing fine differences between the phenotype of the two races for the purposes of this post however; Penny’s (1974) description will suffice:

“ Rostrata has a vinous red head, a chestnut mantle, grey brown under tail feathers and is much smaller”

“Picturata has a grey head, purplish mantle, white under tail and is larger”

For many years it was reported that individuals exhibiting the rostrata phenotype were restricted to the small islands of Aride, Cousin and Cousine. Penny (1974) also cites Fregate which makes sense as though not small it is the most isolated of the granitic islands.

Whilst working on Cousine Island in the mid-nineties I undertook a survey of the turtle dove population on the island. I caught, if I recall correctly, some 120 birds and scored them on various characteristics from plumage colour on various parts of their bodies, eye colour and various biometrics including wing length. Each bird measured was ringed to avoid repetition. At the time my results suggested that 1 in 3 turtle doves on the island still exhibited strong rostrata characteristics. I still have all the data in an old logbook at home one of several topics that fit into the likely doomed “I must write it up someday category…”

In 1995 Chris Feare – yes the same Chris Feare who is now working with us on the Sooty tern project – published a brief paper on his findings of turtle doves on Bird Island. Where, though admittedly with a small sample, his capture and grading of the birds suggested a population very close to the rostrata phenotype. Feare goes on to suggest that a small number of birds were either introduced or colonised naturally in the latter half of the 19th century and had persisted there largely unnoticed until changes in vegetation in the latter part of the 20th century allowed the population to increase.

Although not mentioned in the literature (indeed Hill 2002 states that the birds on Denis are of the picturata form) I have found there is definitely considerable variation in the physical characteristics of the doves on Denis (see photos in sidebar) and though I have not gone to the lengths of capturing and scoring the birds physical traits (too many more important and pressing issues to address) I think the population on Denis may be of interest in that regard.

This is notable because if the population on Denis were scored for its phenotype and then managed over a period of years it may be possible to bring back the endemic rostrata phenotype throughout the population. This due to Denis’ relative isolation could be maintained with just periodic monitoring and management.

A project for the future perhaps…

Refs:
Beamish, T. (1981). Birds of Seychelles. Dept of Agriculture. GoS.
Feare, C, J. & E.L. Gill (1995). The turtle doves of Bird Island, Seychelles. Bull. B.O.C. 1995 115(4).
Hill, M.J. Ed (2002). Biodiversity surveys and conservation potential of inner Seychelles islands. Atoll Research Bulletin. July 2002.
Penny, M. (1974). The birds of Seychelles and the Outlying islands. Collins. ISBN 0 00 219829 0

Sooty Tern Update – encouraging progress!

2009-07-01T01:06:00.000-07:00

Apologies for the delay in posting but paperwork deadlines have kept me very heavily occupied over the last 10 days – here’s hoping the effort pays off!

I paid a 24-hour visit to the island, weekend before last, in order to show some representatives of a potential donor agency the ongoing environmental work on Denis and also highlight some aspects that may be of interest to their organisation.

I made a special effort however to follow up on the sooty tern project during the visit and see how work is progressing and have some very encouraging news to recount.

I observed several birds circling very low over the project area and calling and also observed 3 birds landing. As we have seen before single birds that land, bow and display to the models but of course the models do not respond. However when they land in groups they can display to each other and this is our hope that sufficient birds can be attracted simultaneously down to the site such that they can cross-stimulate each other and begin the formation of a breeding colony.

That day though, I was particularly interested in the behaviour of one bird that appeared to be exhibiting “scrape-making” behaviour. This is the precursor to egg laying and of course a very exciting development for the project. The bird stayed on the ground for more than 40 minutes and was twice attended by another bird – perhaps its mate? See photos in side bar which, although somewhat overexposed (it was a very bright sunny day) and taken at the maximum zoom nevertheless, serve to show the birds on the ground in amongst the models. The bird was down on its chest and displayed the rocking side-to-side motion that accompanies the activity of making a scrape in the ground that it will later lay in. I was not though, due to the lie of the land, able to see whether the bird’s feet were in fact scraping at the ground in order to make a depression. Notably having a left a bird (presumably the same one) did later return to the exact same location. So fingers crossed!

That however is just the least of it! On the morning of Wednesday the 24th June I received a call from the volunteers advising me that 20 birds had been on the ground that morning and that they had observed 3 pairs mating. This is very encouraging and caused me to advise several interested parties including Prof. Feare in UK accordingly.

We are of course still learning as we go; such a project has never been attempted with Sooty terns before and we are continuing to refine the methodology as we progress. These developments however constitute a major advance and give us hope for the future even if this year we do not have birds attempting breed on the site.

Time will tell… check back regularly for updates.

Nature Notes 5.

2009-06-15T03:17:00.000-07:00

Just back from the island, it was a brief 24 hour stay primarily to give a presentation and walk for some guests, so a quick summary of salient points noted below:

Sooty tern (Onychoprion fuscata) update. I stopped by the sooty tern project for an hour or so mid-afternoon on Saturday but only observed a couple of circling flyovers by birds. On Sunday morning however I met Vicki and Georgia at the observation platform and they had quite a lot to recount – most notably that they had observed a pair of terns landing that had courted and mated in the project area… this is most encouraging!!! In addition they had observed a bird attempt to court and mate with one of the plastic models – which goes to show that models clearly do provide the correct kind of stimuli!!! Whilst I was there on Sunday morning I observed a bird circle and land in the location … unfortunately I couldn’t stay and take photographs… but that will be a focus of mine during my next visit.
Observations on a Seychelles warbler (Acrocephalus sechellensis). Much along the lines of my post of June 8th , whilst pursuing one matter – in this case whilst sitting under the observation platform in the shade waiting hopefully for a Sooty tern to land – various other points of interest presented themselves. First my attention was drawn by the familiar clicking of a warbler’s bill as it took insects. The bird was very close by in a clump of low herbaceous vegetation consisting primarily of the spinach plant “Payater” (Amaranthus dubius). This was clearly a very fruitful area for it as it remained in this small clump for a good 20 minutes feeding busily on insects taken from the underside of the leaves. On a few occasions it took a prominent perch and looking above would launch itself straight up to aerially intercept a flying insect. It also paused in a more secluded site to preen. Judging from its behaviour, the somewhat mottled plumage on its breast and the less than rich brown colouring if its eye I got the impression that it was a subadult – probably recently departed from its natal territory and currently “floating” or in the process of establishing a territory for itself.
Ant-lions (Myrmeleon obscurus). Then looking down at the ground beneath the platform I became aware of several characteristic funnel traps of ant-lion larvae in the sand. These funnels with there very loose surface of sand are easily disturbed by passing insects such as ants. At the nexus of the funnel hidden just below the surface the ant-lion larvae lies in wait. When it senses the disturbance of sand in its “funnel” it shoots sand out from the centre knocking the unfortunate prey down into the centre where it is caught and consumed by the waiting predator. I watched fascinated by the occasional shots of sand that were sent out from the centre of each pit.
Carpenter bees (Xylocopa caffra). Finally whilst waiting under the platform I tried to get a photo of a female carpenter bee that was drawn by small flowers in the undergrowth. This has become something of a task for me… I have wanted to do a post on the carpenter bee for quite some time but I can’t seem to get a good photo of the female. I have several good photos of the male but the female with her black body and characteristic single large yellow band is another matter all together!!! The males move slowly from one flower to the next often pausing and hence allowing photos to be taken. The females however whilst much more readily noticed with their distinctive colouration and low rumbling buzz are very flighty seemingly never pausing long enough for me to get a decent photo… I shall endeavour to persevere…
Blue-cheeked bee-eaters (Merops persicus). Moving away from the Sooty tern project… regular readers will be aware of the presence of the beautiful blue-cheeked bee-eater on Denis for the last 6 months (See my post of May 23rd for the full account) and our interest in recording when exactly the last individuals leave the island. It had been thought that all the birds had left after the first week of this month – but during the tour I was giving on Sunday morning I observed two hawking from prominent perches on the island’s southern beach and then later repeatedly heard one near the hotel complex… so a few stragglers yet remain. We will continue to monitor.
Flycatcher news (Terpsiphone corvina). Great news from Mervyn working on the Flycatcher project! A second bird has now fledged successfully giving us much hope for the future.

Outreach Programme – Launch of Denis Island Newsletter.

2009-06-10T04:18:00.000-07:00

I have posted in the past about various aspects of our outreach programme under the islands 2008-2012 Environmental Management Plan. The raising of public awareness both at home and overseas is an important component of the overall sustainability of the island’s environmental initiatives – and this blog forms part of that outreach.

In recent months we have had some excellent national media coverage on the TV, radio and in the press. We also, thanks to the assistance of the Seychelles Broadcasting Corporation, have had some great international coverage on CNN. This has all been very encouraging and has resulted in positive feedback.

We are also active on the island as well; GIF personnel provide walks and talks for hotel guests and the island has also constructed an information centre which now just awaits the arrival of posters and pamphlets on the island’s environment in English and French for it to open.

Now last week we launched an Environmental Update Newsletter for circulation on the island in Guests’ rooms and in the hotel complex. The intention is that there will be an issue every 2 months that will give clients the opportunity, at their leisure, to learn about the islands wildlife and environmental projects.
Simply click on the images below to enlarge and read the first Newsletter.

Sooty tern project – update and Post by Prof. Chris Feare

2009-06-09T22:17:00.000-07:00

I have been to the island 3 times in as many weeks largely due to the need to follow up on preparations for and implementation of the island’s sooty tern project (see my post of 19th May for background information). Professor Chris Feare, the world expert on the species, is in the Seychelles at the moment having come out to oversee the project set-up on Denis. Our two volunteers, Georgia French and Vicki Willits, have also arrived and work is now ongoing.

Following on from our findings last year the models and loud speakers have been set out in the project area. One loud speaker has also been mounted half-way up the trunk of a coconut tree facing out to sea along the prepared entry flight path in order to attract birds that may be flying along the coastline. The southeast monsoon has been late to establish this year and this has a bearing upon the behaviour of Sooty terns – with fewer birds over-flying the island than we would normally expect. The wind has however now set in and we hope that bird numbers will pick up in the next week or two. Despite this, landings have been relatively good with in fact more landings reported in the first week of work this year than throughout the entire season last year! This is very encouraging and underlines I feel, that the lessons learnt regarding the birds’ preferences last year are now reaping benefits in our work. Of particular note was the landing of a pair of birds which then commenced a courting display – exactly what we are hoping for!!!

Chris Feare has kindly written a post (see below) for this blog that sets our work in the broader context of his long term study of Sooty terns in the Seychelles archipelago:

"While Sooty Terns do not command the iconic status bestowed upon some of Seychelles’ rare endemic birds, such as the Seychelles Magpie Robin, Seychelles Warbler and Seychelles Paradise Flycatcher, the Sooty Tern is in fact the Seychelles’ most numerous bird. It breeds in huge spectacular colonies on Bird and Aride Islands, and on the more remote islands of Desnoeufs in the Amirantes, Goelette Island of Farquhar Atoll and Wizard Island of Cosmoledo Atoll. Despite remaining so numerous, Sooty Terns have faced a number of threats since man settled the islands in the mid-eighteenth century. These include the collecting of enormous numbers of their eggs, alteration of the habitats of their nesting islands and the introduction of mammalian predators such as rats and cats. As a result, several former breeding colonies now lie deserted, particularly those on smaller islands close to the main centres of human occupation.
Concern for the species led to their receiving various forms of protection but these are extremely difficult to enforce on remote and often uninhabited islands, and some of the earlier conservation attempts were based on insufficient knowledge of the birds’ biology and behaviour. My own studies of Sooty Terns in Seychelles, now spanning 37 years, along with investigations of colonies elsewhere in tropical oceans, have provided information on their needs and lifestyle that can contribute greatly to their conservation. For example, we know from recent events on Bird Island that restoration of prime habitat, by removing old coconut plantations and encouraging the development of indigenous herb vegetation such as purslane, can lead to a dramatic recovery in numbers. Controlled harvesting of their eggs can also play a part by placing a value on the birds while at the same time regulating the number of eggs that can be taken and the islands upon which harvest is permitted. And eradication of alien predators benefits all indigenous animals, not just Sooty Terns.
Sooty Terns are long-lived birds: on Bird Island ringing studies have revealed several birds 34 years old. In the absence of disturbance, adults usually return to nest on the same island year after year. In an attempt to re-establish a colony on an island known to have supported a large colony 200 years ago, an experiment is currently taking place on Denis Island (see recent blogs). Here, a small area of forest has been cleared and plastic models and broadcasts of Sooty Tern calls are being used, with some success, to attract birds to the island. Once settled, we hope they will continue to return and breed.
Despite our increased knowledge, however, Sooty Terns still hold many mysteries. In particular, we do not know where they feed while they are breeding. Nor do we know where they go when the leave Seychelles after breeding. Ring recoveries in southern India and in northern Australia suggest that they travel far. But we shall not get a better picture of their movements until tiny satellite transmitters, suitable for attachment to Sooty Terns, are available. Only then will we be able to determine whether another of man’s activities, intensive fishing of tuna, presents a threat to these magnificent birds. Sooty Terns do not eat tuna, but they are totally reliant on these predatory fish to drive smaller fish, like sardines, to the ocean surface where they become available to the birds. So if the Sooties prove to feed where tuna are being over-fished, the birds’ populations will be threatened no matter what conservation measures are in place on their nesting islands."

100 posts – one thing leads to another

2009-06-08T22:58:00.000-07:00

This post marks a landmark for the Denis Island Environmental Update blog – it being the hundredth post since I started the blog in July 2008. The blog was established primarily to provide information to hotel clients many of whom return periodically to the island and expressed an interest in being able to follow up on our projects on the island during the time in between their visits.

It did occur to me when starting out that whilst I would initially have plenty to write about it would be difficult after a while to find new and different matters to cover. In fact the opposite has been the case, every visit to the island seems to provide numerous new topics to report on and it is not lack of subject matter but rather lack of time to write them that effectively limits the number of articles I am able to post. Frequently I leave the island with a list of 6 or 7 new topics for potential posts but many fall by the wayside as they are replaced by new options from a subsequent visit before I get the time to actually write them up.

A perfect example of subject overload happened during my visit a week ago. I noted on arrival a sudden and widespread commencement of nest building by the island’s Brown noddy colony (see post of 31st May). I spent some time photographing the birds nest-building in the coconut trees at the entrance to the main hotel complex. Following this I decided to go and try and photo the birds gathering nest material on the beach crest. As I approached the beach however I noted a white tern alighting on a branch next to its chick with a beak full of fish so I was then distracted by this and occupied by attempts to get a photograph that captured the moment of food transfer from adult to chick. I failed to do this but decided to wait for the return of the adult and try again. After a few minutes a white tern did indeed fly into view bearing fish but this was a different adult flying to another chick higher up in the same tree. Whilst trying to feed the chick a small fish was dropped and fell to the ground. This nutritious morsel was immediately picked up by a moorhen which in turn ran off in the direction of a scaevola bush. I suspected that it also had young to feed and I now set off to try and capture that image. The moorhen did indeed have two chicks hiding in the bush and it thereafter sectioned up the fish to feed to its young – paying me no attention whilst I remained still nearby. I stood partly behind the scaevola bush so as not to make the birds feel threatened whilst I photographed the feeding. It was whilst standing there that I noticed that the flowers of the bush were alive with large numbers of a fly with very distinctive red-eyes – so having never previously observed such an aggregation I photographed these insects so as to enable their identification at a later date.

After this I returned to my original plan of going to the beach crest to photo noddies collecting nesting material. I positioned myself on a beach chair and waited for the right opportunity. I was soon photographing several noddies busy gathering casuarina fronds on the beach when I noticed a ghost crab approaching me along the beach. These animals are normally very wary and difficult to photo but as I was stationary on the seat the crab appeared not to notice me and continued to approach so I took the opportunity to photo it also. As it passed along side me I turned in the chair to try and get a better shot but this movement alerted it to my presence and it immediately sought refuge down the nearest crab burrow. I kept my camera trained on the burrow entrance however as I was confident that this burrow belonged to another crab which meant the new arrival would rapidly be forced out by the resident. Sure enough the crab soon appeared at the entrance but seeing me shot back down. This happened a couple more times and I waited, confident that the crab would soon have to emerge and I would have another opportunity to photo it up close. What happened next however really did surprise me and was the first time I had ever observed such behaviour. The crab did indeed re-emerge but this time clasping the resident crab, which was a bit smaller, in its pincers. It then proceeded to castaway the smaller crab and return back into the burrow which it had obviously found so much to its liking that forcible eviction of the owner was the next logical step!!!

I then just walked 30 metres down the beach and encountered 15 Greater crested terns – the highest count I have ever recorded on Denis – better yet they very kindly contrived to position themselves such that I could fit them all in the frame of a single photo thereby providing proof of the new record!

So through the simple idea of taking a photo to complement a post on Brown noddy nest-building one thing had led to another over a period of 30 minutes or so to encounter five other potential articles… so what to write about next?

Focus on warblers…

2009-06-08T21:33:00.000-07:00

The Seychelles warbler (Acrocephalus sechellensis) is an iconic species for Seychelles conservation. In the 1960s the entire global population of only 20-25 birds was restricted to a small area of mangroves on the tiny island of Cousin. This led to the purchase of Cousin by the Royal Society for Nature Conservation in 1968 and the subsequent management by the then International Council for Bird Preservation (now BirdLife International).
The purchase of Cousin in order to save the warbler is often considered the dawn of modern conservation in Seychelles. In the following years natural vegetation was allowed to regenerate on Cousin and the Seychelles warbler population expanded and spread throughout the island. In 1988 warblers were introduced from Cousin Island to Aride and then to the neighbouring island of Cousine in 1990. Both introductions proved to be successful in particular the introduction to Aride where birds were reported to be nest-building within a day of their release on the island! The population of warblers on Aride today numbers more than 2,000 birds and the world population now likely over 3,000 – a most remarkable success!
58 Warblers were introduced to Denis Island in 2004 and follow up surveys of the island population 2005, 2006 and 2007 have shown a steady expansion of the warbler population on the island. The introduction of the warbler to Denis contributed to the downgrading of the threatened status of the species to Vulnerable under World Conservation Union (IUCN) criteria.
Logistical problems meant the island was unable to host researchers in 2008 to follow up on the monitoring of the population but I am happy to report that a survey of the population will be undertaken in 2009 so keep a look out in the coming months for updates on the status of the Seychelles warbler on Denis Island.

Breeding seabirds

2009-05-31T23:33:00.000-07:00

Just back from the island again and more developments to record.

The Brown Noddy (Anous stolidus). In my last post (Nature Notes 4 of 26th May) I recorded that there were currently a lot of white tern chicks in evidence around the island. The first thing I noticed on arriving on Denis on Thursday was the rapid and widespread onset of nest building amongst the island’s Brown noddies. The pathway leading up to the main hotel building was alive with the squawking refrain of the birds from the crowns of all coconut trees. The Brown noddy builds a simple though often rather large and untidy platform of twigs, casuarina fronds and sea weed at the base of the palm leaves where the large stem forms a natural gully where it joins with the trunk of the tree. The coconut trees in the hotel garden are particularly busy with many of the trees harbouring 3 or 4 nests. This density is not reflected elsewhere with trees typically having only 1 or 2 nests per crown. I am not sure why this should be, but I am inclined to think it is linked to the spacing of the trees and the lack of other canopy which provides easily navigable flight paths for the birds to access all the suitable nesting niches a tree has to offer. This coupled with the relative shortness of the trees in this open environment means they are sheltered from much of the wind by the hotel, readily accessible and yet secure – making them ideal for nesting.
I spent a while trying to get some photos of this nest-building activity – one bird would remain on the nest platform whilst the other would fly back and forth gathering and bringing material which it would then give the other which would incorporate it into the nest structure. The noddies were particularly busy collecting nesting material on the beach crest around the hotel where the last high-tide had washed up a lot of suitable material. The arrival of the bird bringing material would initiate another burst of harsh calling between the pair including bouts of their distinctive, bond-forming nodding behaviour which gives the birds their name.

White-tailed Tropicbird (Phaethon Lepturus). I also reported in my last post the return of the tropicbirds to the nest site that successfully produced our first confirmed fledging from a ground nest for this species. I checked on the nest again on Saturday and the bird was still present presumably incubating. The nest site is immediately adjacent to the path and I hence decided to cut a palm leaf and lean it against the Casuarina trunk thereby screening the nest from passersby on the path and thus hopefully reducing somewhat the stress on the birds – I will provide feedback periodically. We also now have a fourth confirmed ground nest on the island. This nest north of the runway and behind the staff quarters at “L’Allee Coco Rouge” is cosily placed amongst some old logs and currently contains a well-developed chick (see photo in sidebar).

I have been following the development of Denis as a seabird colony in detail on this blog. It is of significant interest to record the recovery of seabird populations following the cat and rat eradications in 2000 and 2002 respectively and Denis is making good progress.
The island currently supports breeding populations of: Brown Noddy, White terns (Gygis alba), White-tailed Tropicbirds and Wedge-tailed shearwaters (Puffinus pacificus). The island also supports a large roosting population of Lesser Noddies (Anous tenuirostris) which we hope may in time develop into a breeding population and of course the island is actively undertaking a project to re-establish a Sooty Tern (Onychoprion fuscata) colony.

Nature Notes 4

2009-05-26T23:36:00.000-07:00

Notes from my last visit to the island and quite a few items of interest to report:

Magpie-robin news – firstly and sadly I have to report that we appear to have lost the poorly female that I reported on in my post of May 19th. There being no flight on Wednesday of last week the antibiotics, syringes etc… could only be taken to the island that Thursday and Catherina has not sighted the bird since Wednesday and we must now fear the worst. We do now however have a fresh stock of antibiotics with a long shelf-life on the island being kept in the fridge in case it should be needed in the future.
Flycatcher news – on a positive note our first flycatcher fledgling (see post of 21st April) appears to be prospering and there are currently 3 other breeding attempts ongoing in other territories.
White terns (Gygis alba) – we have been having a prolonged period of very hot weather in the central archipelago. There is typically a period of 3 or 4 weeks in April/May when the wind drops and the weather is very hot and dry before the next season establishes – but this year it has been going on for a couple of months. A change in the wind can effect water temperature and prevailing currents which in turn impacts upon the availability of the small fish that sea birds depend on to feed their young. The impression on the Denis at the moment however is that food is in abundance as we are experiencing a marked surge in the number of young white terns on the island. Let’s hope that food availability remains sufficient to see them through to independence.
White-tailed tropicbirds – I am delighted to be able to report that the site that produced our first confirmed tropicbird fledgling from a ground nest since the eradication of rats in 2002 is once again occupied by the female. Those regular readers of the blog will recall how I followed the development of “Tina” last year in detail on this blog and was delighted to report her successful fledging in the week of Christmas. Well her mother is now back on the nest site and possibly already incubating another egg. Another great benchmark in the recovery of the island’s ecosystem!
Greater Crested terns – birds are still to be seen each morning at Pte Mme Guichard and then in the afternoon on the sandstone outcrops just off the southern coast. There are currently nine birds in residence.

Observations on the Blue-cheeked bee-eater (Merops persicus)…

2009-05-23T22:16:00.000-07:00

Now into the fourth week of May and the Blue-cheeked bee-eater is still a common sight on Denis. My impression is that numbers have increased again over the last month with perhaps 30 or more on the island. Following the major influx in November when some 500 or so birds descended on the island. I recall watching literally hundreds hawking over the runway in the evening at the end of that month. The island was alive with these bright green birds with, so it seemed, practically every prominent perch along the paths occupied by yet another bird and their “trilling” call to be heard everywhere.

Numbers rapidly dropped after a few days but a few have been present ever since. During April the numbers went up again presumably as birds were passing through Seychelles this time on their route back north to their summer breeding grounds in southern Asia. Coming to the island on May 21st I frankly didn’t expect to see any as I presumed they would have all flown North by now – but the first bird call I heard as I got of the plane was that of a bee-eater and I could see 4 of them hawking over the beach by the runway. Later that day I saw several more along the east coast at Belle Etoile and more again around the hotel complex and late that afternoon I observed ten to a dozen feeding over the runway.

The next morning I went to photograph the beach outside the main hotel complex as part of a long term study of beach movement and erosion that I have been doing since 2005 when I encountered another bee-eater hawking from a perch on a fallen tree branch that had been washed up. I have learnt over the last 6 months that the bee-eaters are very alert and rather cautious and generally won’t let you get at all close before moving on. This bird however was otherwise occupied as the inshore breeze early that morning appeared to be channeling insects along the coast right past its vantage point. It was therefore very busy securing its breakfast and seemed little concerned with me.

Every 30 seconds or so it would dart of its perch in pursuit of an insect catch it and then stunt and turn in amazingly tight arcs to return to its original position to await its next passing snack. Over the next half-hour I utilised each of its forays to edge incrementally closer to its perch then as I got within about 10 -12 metres the sun came out from behind the clouds and giving good light to photograph the bird and capture the stunning colours of its plumage (see side bar). I was absorbed by this process; with every flight I got a few inches closer and so I believed each set of photos would be that little better than the one before.

I was then fortunate enough to observe some very interesting behavior. The bee-eater returned to its perch with a very large prey in its beak aptly enough it was a large bee – a male carpenter bee in fact.The bird then proceeded to beat the bee against the branch giving off a surprisingly loud “Thok, Thok, Thok” drumming noise as the insect’s exoskeleton hit the wood. Finishing off this bee was not to be an easy task however, despite this vicious beating! One such hit served to dislodge the bee from the bird’s beak and it was off… in a low careering flight over the sand away from its would-be captor. The bird was immediately in pursuit and in the space of 20 feet had re-captured its prey and then promptly returned to its perch to continue the drumming! This scene played out four times. Four times the bee escaped and flew for its life, four times the bee-eater shot after it recaptured it and returned to its post to continue the assault. It was fascinating to watch the blend of beauty, savagery and efficiency embodied by this stunning bird. The blows were administered by a severe whipping action of its head and neck a photo in the sidebar shows how the bird has actually turned its head 180o in order to imbue the whip-lash action with optimal force! Eventually the bee was subdued and then promptly consumed – the whole process from first capture to swallowing had taken a good 4-5 minutes.

The bird then continued with its business and I with mine edging progressively closer in search of that “perfect” photo and then suddenly it was gone. I waited for another 5 – 10 minutes in the hope it may return but it had flown off south-west down the coast doubtless to find another strategic point to continue its hunting.

I was very pleased with my morning’s “work” and I think – and I hope you agree - I was able to catch some good images of this truly wonderful bird.

Sooty tern (Onychoprion fuscata) project – year 2

2009-05-19T23:17:00.000-07:00

It’s getting round to that time of year again! I have just received a shipment of new models (see photo in sidebar) so we can increase the density of models in the trial area this year. These models are closer to the actual size of the Sooty tern and are in fact magpie models that have been re-painted to appear like Sooty terns. When Denis was first discovered in 1773 it hosted very large seabird colonies including a large population of Sooty tern. Human impact on the island over the next hundreds years was very extensive and it is likely that the ground nesting sea bird colonies were extirpated within that period.

The environmental management plan for Denis has set aside the southern portion of the island for restoration to as close as possible to how it was when first discovered. The attempt to re-establish a colony of Sooty terns on the island forms part of this initiative.
The project commenced last year (see my posts of 2nd July, 21st September and 13th October 2008 for more information) with the preparation of the habitat area and the trial of different habitat and stimuli combinations including 2D and 3D models and the broadcasting of colony noise from loud speakers.

The first year of work and its structured approach allowed us to learn a good deal about the preferences of the birds and the trial area will be set out this year to reflect those findings and we are optimistic about the potential for 2009.

We are working with Dr Chris Feare who is a leading ornithologist and has been working on Sooty terns in Seychelles for many years. Chris will be arriving at the end of this month along with a couple of volunteers who will assist with the monitoring of the scheme this year - as well as undertaking other work.

I will report regularly on the project and its progression – success is by no means guaranteed but we are again breaking new ground here on Denis Island and should we achieve our objective it would represent another world first for the island - so do keep checking back for news on the Sooty tern project over the coming weeks…

A poorly Magpie-robin…

2009-05-19T04:48:00.000-07:00

I received earlier today a call from Catherina on the island telling me that she had sent an e-mail with photos of an adult female SMR that was showing signs of ill-health. The posture, plumage and behaviour of the bird were not good and furthermore its droppings were liquid.

E-mail communications followed with Rachel Bristol and I then spoke with Dr Melanie to the vets department on Mahe. It was decided to get a broad-spectrum antibiotic that could be administered by injection to the bird. So I then went to the vets department purchased a bottle of Oxytetracycline and the smallest syringes and needles available.

The treatment entails capturing the bird and injecting 0.1ml into the bird’s muscle tissue and repeat in 3 days or so. This method has been used successfully previously on SMRs. So it is to be hoped that this problem is based upon a bacterial infection and that the treatment reaps benefits.

Unfortunately by the time I got the call from Catherina it was already too late to catch the plane and there being no flight on Wednesday we will not be able to get the medicine to the island before Thursday – hopefully it won’t be too late.

The tetracycline has a long shelf life so we can keep it in the fridge on Denis for about a year and use it on other birds should the need arise.

Check back regularly for news on our poorly magpie-robin.

The Seychelles Flycatcher (Terpsiphone corvina): whiskers, “hair-dos” and mimicry…

2009-05-14T00:54:00.001-07:00

In my post of 9th April I wrote about the whiskers clearly evident on the faces of both male and female flycatchers (Terpsiphone corvina) and postulated on what their purpose might be. Whilst drafting that post I spoke to Rachel Bristol, Project Officer on the Flycatcher project. We talked about the whiskers and Rachel also commented on head plumage of the birds referring to it in her inimitable style as a “spiky hair-do”. Rachel subsequently sent me a wonderful photo of a male flycatcher in hand which clearly illustrates both features (see sidebar).

Then after her last visit to Denis, Rachel called to update me on her findings and mentioned something new of real interest namely that the Seychelles magpie robins (Copsychus sechellarum) in some territories had begun to imitate the song of the Flycatcher.

I have in the past written about the ability of Mynah birds to mimic the calls of the Seychelles magpie robin on Denis. The Mynah is a renowned mimic and I would not have been at all surprised if they had already begun copying the Flycatcher’s call and causing confusion in Rachel’s attempt to monitor the flycatchers on Denis. The Seychelles magpie robin is another matter and this is of particular interest because until the introduction of Flycatchers to Denis in November the two species had not co-existed on an island for a hundred years or more. This co-existence is therefore a new experience for the all the birds and also a time of great interest for ornithologists to see how the two species will interact. The feeding niche of the two species is largely distinct and their territories overlay each other on Denis without any evidence of negative interaction but the Magpie robins adopting the song of the flycatcher may conceivably lead to some confrontations in territories – at least in the short term

I was involved with the transfer of Magpie robins to Cousine Island in 1995. The overall population was much lower back then and the habitat on Cousine despite my efforts over the preceding year or two was still limited for the species. As such a very precautionary approach to the introduction was undertaken - two young surplus males from Fregate were introduced to the island and latterly an old male which had been displaced from its territory on Fregate and following injury had been nursed back to health by hand. These birds were surplus and somewhat expendable and the intention was to see how they fared on Cousine before any precious females would be risked. (The birds did settle and the old one ended up fathering more offspring when females were latterly introduced). Initially however what was remarkable was the very limited song variety of the young males. One of them just continually repeating the same three note refrain until it would put one’s teeth on edge! When the old male was introduced however he had an extensive variety of tunes suggesting that birds acquire/learn new songs over time and are not born with a pre-programmed repertoire. This thought was re-enforced when the younger males began to expand their own tune list once the old male had been introduced.

Now here on Denis nearly 15 years later we have further evidence of the capacity of the Magpie robin to learn new tunes and styles.

Observations on the Seychelles blue pigeon (Alectroenas pulcherrima)

2009-05-13T04:19:00.001-07:00

In my post of 10th August 2008 I wrote at length about the colonisation of Denis by Blue pigeons over the last 10-15 years and how today the island hosts a quite large and healthy population. There are no earlier records of blue pigeons on the island from visits in the early and mid-20th century or the 1970s so it would appear that man-induced changes have created suitable habitat on the island to enable it to establish a population on Denis.

In particular human activity has introduced various broadleaved tree species such that today some 30% of the island has a broadleaf canopy – and ongoing vegetation management programmes means this is likely expand considerably in the coming years.
Of particular note however are the fig (Ficus nautarum) and banyan trees (Ficus benghalensis) which now prosper on the island. The blue pigeon particularly likes to feast on the fruit of these trees. The small bright red fruit draws the birds in flocks to even very young trees – with at least 23 birds being counted in just one fig tree in 2008.

I have also frequently observed birds feeding on the white berries of the coastal bush “Veloutye” (Scaevola sericea) in the hotel grounds and around the southern point. During my visit last month I was able to capture a good photo of this behaviour (see sidebar). During the heat of the day it also common to see them in small groups perched in Bwa Kassan (Guettarda speciosa). The impression I receive of this behaviour is that the heavy shade offered by this coastal tree is ideal for the birds to shelter when the sun is high in the sky without them having to stray too far from a berried Veloutye bush.

Evidence of regular breeding continues with juveniles frequently being seen around the island – including one instance of twins I encountered a few months ago. The Blue pigeon is a remarkably beautiful bird with its red wattle and eye, powder grey neck and slate blue wings and lower body. The juvenile is very different however with no red colouration and drab grey and slate plumage with a tinge of an almost moldy green to the wings. One juvenile very kindly perched conveniently for me to photo in April (see sidebar).

Nature Notes 3

2009-05-08T01:52:00.000-07:00

A belated summary of various observations following my visit to the island 16-18th April:

Blue-cheeked bee eaters (Merops persicus): I was very interested to find bee-eaters still present on the island we have had some birds stay on the island since the mass “invasion” in November when some 500 turned up for a period of days. Numbers rapidly declined after that, but there have always been some on the island since then. Interestingly during this last visit numbers definitely appeared up compared to March with several birds at a time to be seen hawking over the runway and from bushes along the east coast. A few days later I received an e-mail from Adrian Skerrett of the Seychelles Bird Records Committee (SBRC) asking whether Denis had received a new influx of bee-eaters as other islands had reported new sightings. It appears that birds heading north again to summer breeding grounds have passed back through the Seychelles archipelago. The mass influx of November and this return has apparently been seen throughout the archipelago and Adrian is working on a paper that summarises this migration pattern over the last 6 months. It is difficult on an island the size of Denis to estimate the number of bee-eaters that are present at any one time but I would have guessed there were approximately 20-25 on the island during mid-April representing an increase of 10-15 from March.

Whimbrels (Numenius phaeopus): A very distinct decline in Whimbrel numbers was evident. In November I counted a single flock of some 115 birds just on the reef flats off the North east coast and they have been abundant throughout the northern winter. A few birds stay all year on the island – presumably sub-adults – but it is clear that the bulk have started to return north again with only a few to be seen in small groups around the island in April.

Greater crested terns (Thalasseus bergii): a common sight in the morning at Pte Mme Guichard and later in the day on the sandstone outcrops just of the islands southern point – there currently appear to be nine birds on the island.

Grey Heron (Ardea cinera): The grey heron I first recorded in February is still resident spending quite a bit of its time now on the northern beach of the island hidden in amongst the fallen trees that project out across the beach and into the sea there.

Green turtle (Chelonia mydas). During my usual rounds I encountered my first green turtle track of the year – Green turtles can nest all year round but they show a distinct peak in nesting activity in the May-July period.

The island’s cattle have been kept north in the farm area at the estate for several months – being fed primarily on coconut shoots. This has allowed the vegetation at Belle Etoile to recover significantly in particular the Indian Mulberry trees (Morinda citrifolia), which the cattle particularly like to browse, have re-sprouted dramatically giving the pasture a more of a shrubland look. I also noted a lot of cotton plants in seed. Cotton (Gossypium hirsutum) was grown on Denis in the 1830s – 1850s and was a major cash crop for Seychelles at the time. Despite it being over 150 years since its cultivation it can still be seen in scrubland areas on the island. It has also been quite a weed in our sooty tern project area where removal of the coconut trees last year created the space and disturbed ground it needs to prosper.

Observations on Great and Lesser Frigatebirds (Fregata minor and F. ariel).

2009-04-27T00:12:00.000-07:00

The Frigate bird is an iconic species in Seychelles - soaring on the breeze a large dark bird with its characteristic arched wing profile silhouetted against the bright blue sky - it has been adopted as a symbol by 3 islands in the central archipelago. Both species can be seen quite regularly in the central archipelago, though neither breed here, their nearest large breeding colonies being situated on Aldabra.

Aride island hosts the largest roost in the central archipelago with a seasonal peak of some 4,500 birds. Skerrett et al (2001)[1] states that small roosting populations also occur on Cousin and Bird Island. I lived on Cousin (1990-91) and clearly recall Frigatebirds roosting in a single casuarina tree, ignoring all others, north of “Anse Fregate”. That tree latterly fell however and I do not know whether the small roosting population on Cousin persists today. What I do know however is that Denis harbours a regular if small roost of some 40- 50 birds. Both species are represented though as is normal throughout the central archipelago the great out number the lesser.

On the Saturday morning of my last visit to the island I observed 6 frigatebirds stunting and swooping at not too high an altitude over the runway so I took some photos in the hope that the results would be good enough to differentiate between the species for the blog.

The photos are not the best – standing looking almost directly upwards, trying to zoom on and photograph rapidly moving birds not being one of my strong points! – but they are sufficient however to discern identifying characteristics.

The lesser frigatebird adult has the abbreviated white chest and inner wing patch, whilst the adult male great frigatebird is entirely black save for its red throat patch (barely visible in the sidebar photo).

Interestingly I was also able to photo two immature great frigate birds one white-headed and one buff-headed. Skerrett et al (2001) state that the white-headed birds are from the Aldabra colony whilst the buff-headed sub-adults originate form breeding colonies even farther afield! Click on the images below to enlarge.

[1] Skerrett et al (2001). Birds of Seychelles. Helm Field Guides, London.

A familiar and punctual friend – the Danaid Eggfly (Hypolimnas misippus).

2009-04-23T22:23:00.000-07:00

During my island visit last weekend I encountered a familiar friend the diadem butterfly or Danaid eggfly. During the mid-90s I worked on Cousine Island and recall seeing this beautiful butterfly, the male of which has a very distinctive wing decoration of 3 large clear white spots on a sooty brown background (see photos in sidebar), in successive Aprils. When I subsequently moved to Mahe I was struck by the fact that I again saw the butterfly over several years on successive Aprils.

This seasonal punctuality has continued on Denis I had regular sightings of the species last April flitting rapidly along the woodland fringe at Belle Etoile and then I had the opportunity to photograph a female in the hotel gardens (see sidebar). This last visit to Denis I encountered two separate males exhibiting territorial and display behaviour and was also able to get some good shots of one of them hence enabling this post. The species is dimorphic with the female being a mimic of the plain tiger butterfly (Danaus chrysippus) but also showing variations in form.

Gerlach and Matyot [1] state that the species is seasonal with adults flying from December to April - but they also note that they are most commonly observed in March-April.

H. missipus is a common butterfly with a pan-tropical distribution and polyphagous eating habit. It is known to feed on species of Asystasia, Portulacaceae and Ipomea all of which are common and abundant on Denis and so it seems likely that this beautiful butterfly will grace Denis for many Aprils to come.

[1] Gerlach, J. & Matyot, P. (2006): Lepidoptera of the Seychelles islands. Backhuys Publishers, Leiden, The Netherlands.

Flycatcher – Breaking News

2009-04-21T00:53:00.000-07:00

I have fantastic news to report! I received a call from Rachel Bristol, the Flycatcher Project Officer, yesterday confirming that we now have our first fledgling Flycatcher on Denis!!! This represents a major breakthrough – it is after all the first Paradise flycatcher to fledge from a translocated population and the first real sign that we are making progress with the species and its long term conservation[1].

It also comes as a significant relief as some dozen previous attempts had proven unsuccessful. Some failures were due to infertile eggs but several chicks have also been lost to unidentified causes though we strongly suspect our old enemy the Mynah bird!
The problem is without constant observation of the nest it is very difficult to ascertain a specific cause of a breeding failure. A few years ago when I was in Government employ we monitored Seychelles white-eye nests to assess causes of breeding failure using special cameras. Rachel and I have discussed this option and she will be seeking funding to try and finance a couple of cameras so that we can get a better understanding of the factors involved. In the meantime however the Mynah remains suspect number 1 and we mean to address the problem ASAP.

The chick that has fledged is from one of the nests filmed by SBC during their visit last month (See post of April 3rd). This chick hatched on Monday the 30th of March (See post of April 9th) and was expected to fledge on the 13th or 14th of April.

When I visited Denis last week however, I spent about 30 minutes in the territory and found no evidence of a chick and feared the worst. Rachel came up the next day and also could not find a chick plus she also observed two adults nest-building nearby giving a strong indication that the previous breeding attempt had failed. So I left the island on Saturday disappointed and believing that we had lost another chick. Thankfully however Rachel has subsequently observed the fledgling being tended to by its mother – the new nest being built actually belonging to another pair in an adjacent territory!

So great news… and hopefully just the first fledgling of many, though we are now approaching the end of the breeding season, we can look forward to next season with much more hope.

I don’t have any photos of the fledgling yet but hope that Rachel or Catherina may be able to get some… keep checking back for updates on our the first Denis island Paradise flycatcher!!!

[1] This transfer of the Seychelles Paradise Flycatcher was been a collaborative effort. Approval was granted by the La Digue Development Board. Donor funding was received from the UK Darwin Initiative. The overall project leader is Dr Jim Groombridge. Project partners include: Nature Seychelles, the Seychelles Department of Environment, the Durrell Institute of Conservation and Environment, the Royal Society for the Protection of Birds, Wildlife Vets International, RARE UK and the University of Kent.

Seychelles Magpie Robins – the next generation.

2009-04-20T22:21:00.000-07:00

During my last two visits to Denis I have had the opportunity to follow up on the status of some our sub-adult magpie-robins. As reported previously we have faced some problems with SMR breeding attempts. Mynah birds have caused real problems – destroying nests and taking/attacking chicks – whilst we have also now had two chicks born with leg abnormalities which have lead to their demise.

There have also been successes however – in particular the two juveniles that Catherina has raised by hand. Catherina’s “babies” named Charlie and Spencer are both well able to fend for themselves and appear to be prospering. They have not forgotten their adoptive mother however and frequently turn up at her place begging for food! During my previous visit I was walking with Catherina towards her place when both birds approached her on the path and began begging. It was amazing to watch as they followed her to her house and then apparently accepting each other’s presence began feasting on the bowl of insects and grated boiled egg she provided them (see photos in sidebar).

I also during that visit encountered the juvenile in territory 1 it very obligingly posed in a nearby bush for photos and the brown barring on its white wing patch which identifies it as a sub-adult is clearly visible (see photo in sidebar).

This last weekend I visited the island again and encountered the territory 1 juvenile and its parents on several occasions. They were notable because the behaviour of the birds was unusual. I first noticed them as I walked from the airport, having just arrived, to the main hotel building. The juvenile was perched amongst some giant tortoises in the tortoise park this is quite normal as SMRs have learnt that the large reptiles disturb the ground where they pass often revealing insects which the birds eat. What was unusual was the constant “churring” call that the adult was making. This call is typically a sign of aggression or stress in the bird. Over the next two days I repeatedly heard churring coming from this territory and then on Saturday morning I observed both adults in pursuit of their offspring! It turns out that the adults are now undertaking another breeding attempt and clearly have decided that one juvenile in the territory is enough!

This behaviour is in fact normal for Magpie-robins but can of course put the ousted sub-adult under a lot of stress – so we will monitor this sub-adult (ringed orange/orange). If it establishes a small sub-territory adjacent to its natal area we will set up an additional supplementary feed station to cater for its needs.

Keep checking back for updates…

Infrastructure and Land Use

2009-04-20T03:54:00.000-07:00

Flying out of Denis the other week I was able to take a few aerial photos of the island as we banked away – whilst not the best due to the slightly fogged windows of the plane they are however sufficient to give an impression of the layout of infrastructure on the island. It is therefore opportune to give readers an overview of the island’s Land Use Plan (LUP).

The Environmental Management Plan for Denis (2008-2012) is based upon LUP which sets out five categories of land usage listed and set out in the photo graphics below:

Zone A: Primary Production Area: designated for intensive human activity, infrastructure placement and production landscapes.

Zone B: Secondary Production Area: designated primarily for production landscapes and low-density tourism/residential infrastructure.

Zone C: Conservation Management Area: designated primarily for management to attain conservation/biodiversity objectives.

Zone D: Ecosystem Restoration Area: area designated for restoration to island’s natural state. All other activities are subordinated to that end.

Coastal Zone: Land within 25m of high water mark – designated for management to optimise natural vegetation cover, structure and function for specific defined ends depending on locality – no permanent infrastructure.

The graphics below show the land zonations and also the main areas of infrastructure of human activity (simply click on the photos below to enlarge). The photos in the sidebar can be used to better interpret the second graphic below.

The LUP is the foundation upon which other aspects of the EMP (such as Biodiversity plan and ecotourism plan) are logically built.

Key:

Yellow: Staff accommodation & related infrastructure.

Blue: Workshops, generator house & fuel storage.

Pink: Livestock areas.

Dark Green: Vegetatble and fruit production.

Light Green: Hotel complex and guest villas.

Brown: Incinerator and solid waste sorting area.

Observations on the Seychelles Paradise Flycatcher…

2009-04-09T04:21:00.001-07:00

The Paradise flycatcher (Terpsiphone corvina) is classified as Critically Endangered on the IUCN Red List of threatened species. The first ever translocation of this species was undertaken to Denis in November 2008 when 23 birds were released on the island over a period of two days.
In my previous post (Friday April 3rd) I recorded that SBC had come to Denis to do a film and radio shows on the Flycatcher introduction project. During their visit they were able to film two nests with birds incubating eggs and whilst I was with them I took the opportunity to take some photos and make some observations. We can not venture close to the nest so I was at the maximum zoom and digital enhancement the camera could offer. This coupled with heavy shade in this area means my photos are not the best they are sufficient however to highlight the observations.

Nest Structure:
The two nests showed an interesting variation in design. The first was constructed on the fine end of a down-hanging branch of a young Takamaka tree and looked rather precarious, the nest secured in position by being interwoven with a couple of leaf stems. The second was in the fork of a young sapling-like “upshoot” from an otherwise fallen Indian almond tree; but it looked all together more solid, being secured to the three woody stems of the fork.
The nests were also notable for their adornment with white materials. One appeared to have small pieces of white cotton, presumably plucked direct from the wild plants that still grow on the island. The second, meanwhile, was clearly festooned with white feathers. Rachel Bristol advised me that the birds in the source colony on La Digue also typically decorate the exterior of their nests with white materials. The only reason I can think of for this (and this is pure speculation) is that it may serve to break up the outline of the nest in the dappled light that typically penetrates through canopy making it harder for potential predators to discern.

Incubation, Nest Guarding and Chick Feeding:
During the SBC filming on that Saturday evening and Sunday morning we observed the the females incubating and then the male guarding the nest from a nearby perch when the female left it periodically. On the Monday morning however I returned to the nests and noted in one that the male tended to the nest directly including sitting in it. As I watched I realised that the male was in fact bringing insects to the nest meaning that the egg must have hatched in the last 24 hours. Over the next 20-30 minutes I also observed the female bring insects confirming the hatching.

Whiskers on Flycatchers:
On examining my photos a few days later what struck me was the prominent “whiskers” displayed by both male and female birds. The Flycatcher feeds predominantly by “hawking” i.e. the taking of insects on the wing. This requires high precision and fine last-second adjustments as obviously the prey will attempt to avoid being taken if they possibly can. I can only imagine that the whiskers enable the final adjustments through tactile stimulation to catch prey when they are perhaps too close to be properly seen.

Click images to enlarge. i). Male at nest. ii). Female bringing insect to the nest. iii). Whiskers evident on the female and (iv). male.

Seychelles Broadcasting Corporation visit Denis Island.

2009-04-03T04:26:00.000-07:00

Last weekend Denis played host to a team from both SBC TV and radio. The primary reason for their visit was to record programmes about the introduction of the Seychelles Paradise Flycatcher (Terpsiphone corvina). 23 Flycatchers were transferred from La Digue to Denis in November of last year in the first ever transfer of this critically endangered species (see posts of 5th and 16th January for more information)[1]. Prior to the transfer the only breeding population of the bird was restricted to the island of La Digue where its habitat is coming under increasing development pressure. It is very important to establish additional breeding populations of the species on other islands so as to reduce the risk from stochastic events such as storm, fire or disease that a single population in a restricted area is prone to.

To assist with the coverage I asked Rachel Bristol the Project Officer responsible for the flycatcher transfer to also visit the island so she could give the necessary interviews. Filming and recording went very well with the cameramen getting really good footage of females on two separate nests and a male in close attendance in one territory.

In addition to covering the flycatcher project, film and interviews were also taken on the progress of the Magpie-robin project, the woodland conservation project and more generally about the natural history of the island – including footage of bee-eaters perched along and flying over the runway.

The SBC crew also visited the new “Belle Etoile” Villas, filmed them and interviewed the Hotel Resident Manager Mr. Paul Horner about this new initiative for the national tourism programme “Check-in”.

The natural history filming was for the national environmental TV series “Karnen Lannatir” whilst the radio recordings were for the weekly radio show “Nature Watch”. Whilst drafting this post I have just spoken to Lucille Adrienne who produces the radio show and she advised me that she has sufficient recording for 3 and possibly 4 fifteen minute spots – including good recordings of the song of the Flycatcher and the bee-eaters so that should make for an interesting listen. The programmes will go out on SBC MW as of next week at Thursday 11:30 hrs and repeated Friday 17:15 hrs.

This latest media coverage is another plus for GIF’s Public relations and outreach programme that seeks to raise awareness of the achievements of the ongoing work on Denis Island. Our sincere thanks go to: the SBC crew Mr. Jerome Dogley, Mme. Lucille Adrienne, Mr. Claude Vidot and Mr. Guilmer Philoe for their interest in the environmental work on Denis Island; and Mme. Lena Desaubin from the Department of Environment for facilitating arrangements.

[1] The transfer of Flycatchers to Denis was: enabled by the agreement and cooperation of the La Digue Development Board, and the partnership and support of UK Darwin Initiative, Nature Seychelles, the Seychelles Department of Environment, the Durrell Institute of Conservation and Environment, the Royal Society for the Protection of Birds, Wildlife Vets International, RARE UK and the University of Kent.

Nature Notes 2

2009-03-31T03:39:00.000-07:00

Just back from a weekend visit to Denis, much of the time was spent with an SBC film and radio crew so more good media coverage which I will post about later.
It’s been awhile since I was on the island so there is a lot to report, other work commitments permitting I hope to have several posts up for readers over the next few days. I’ll start off with a few notes on various natural history observations:

Fody Feeding Frenzy – there is a palm tree at the entrance to the hotel which is in flower and causing great activity amongst Madagascar fodies. The inflorescence was teaming constantly for 2 days with squabbling fodies. Despite watching quite closely I am still not sure upon what exactly the birds were feeding. They appeared to be particularly interested in the flowers, perhaps taking pollen/nectar but also perhaps feeding on insects drawn to the flowers. Their attention was however not restricted to the flowers perhaps feeding on insects or young parts of buds elsewhere on the inflorescence. Regardless they were numerous, combative and very vocal… so there must have been something good there!
More Mynahs!!! – I am reluctant to mention mynahs again having posted extensively on them recently (see post of March 17th) but I got the distinct impression that their numbers are on the increase particularly around the hotel. I also encountered our king Mynah (Lerwa marten) again in its usual locale at Belle Etoile and though he continues to be shy I got a better photo of him (see sidebar) though it was at long distance.
Grey Heron - the bird I first reported on February 15th is still on the island (might it perhaps be taking up permanent residence?) and it continues to be wary. I saw it at Belle Etoile and I was able to take a few long distance photos; but when I tried to be clever and maneuver myself closer by using some thick vegetation for cover it knew exactly where I was. So having belly-crawled to my near perfect vantage point and just brought the camera up to my eye the heron took flight north… clearly still smarter than this observer!
Bee-eaters still with us… - interestingly some blue-cheeked bee-eaters (Merops persicus) are still with us. Having arrived in large numbers in November of last year a few have remained ever since. It’s hard to tell how many remain on the island. I saw 6 together “hawking” over the runway in the afternoon but also encountered individuals around the hotel and along the southeast coast. I would guess there are approximately 10-12 on the island.
Crested terns – these beautiful birds are still to be encountered at Pte Mme Guichard or the offshore rocks on the southern point but there appear to be only six at the moment.
A new restaurant visitor – finally in my post of February 23rd I talked about the nature and different rare species that guests could see, simply while taking breakfast on the Restaurant verandah. Well we can now add magpie-robin to the list. On Sunday morning I watched a magpie robin fly into the restaurant perch on a table and begin to sing! It then spent the next 30 minutes or so in and around the area. It is a single male that has taken up residence around the main hotel building apparently establishing a close relationship with the gardening staff following them closely when they rake in the morning and feasting on the insects there work exposes!

Denis Island contributes to knowledge on migratory birds…

2009-03-25T04:21:00.000-07:00

Over the preceding few months I have periodically posted on our observations of migratory birds. Denis’ position on the north of the Mahe plateau makes it a very interesting location for migratory birds as for many it may represent their first landfall in some 1000 miles of flying over the Indian Ocean! This strategic position makes the island a magnet for exhausted or storm blown birds. Despite this bird records from Denis are rather sparse simply because there have rarely been ornithologists on the island for any extended period. Over the last year or so however the combined activities of various researchers visiting for different projects, the presence of Catherina, my periodic visits and the interest of an island resident have allowed us to start building up a generalised picture of what birds are visiting the island or actually overwintering on the island.

We are not yet undertaking any standardised monitoring as we lack sufficient personnel to do this, so observations are purely ad-hoc or opportunistic nevertheless they are not without value. The Seychelles Bird Record Committee (SBRC – you can connect to their site via the link in the sidebar of this blog) is the agency that compiles records of birds in the archipelago as per the objectives bulleted below:

To collect information and records relating to the status of all birds observed from the islands of Seychelles and their surrounding ocean (EEZ).
To assess reports of all birds considered to be of less than annual occurrence within the Seychelles EEZ and to permanently maintain the original bird record submissions made by observers together with all Committee comments and votes.
To publish summary details of all accepted records, encourage publication by observers of first records for Seychelles and to maintain a national list of bird recorded in Seychelles EEZ.
To provide all persons or bodies interested in the study of birds in Seychelles with scientific data pertaining to bird sighting records.
To increase awareness of and interest in the birds of Seychelles both nationally and internationally.

I liaise periodically with Adrian Skerrett of the SBRC regarding sightings on Denis and on occasion he may request that the observer(s) submit a record sheet if the sighting is of a species that is not considered an annual migrant to the archipelago. The record sheet is then assessed by the SBRC which if it deems there is sufficient evidence to substantiate correct species identification will accept and publish the record. In this vein I have received notice from Adrian that the following recent sightings from Denis have been accepted by the SBRC:

Purple Heron (Ardea purpurea) – One immature bird sighted at Belle Etoile, Denis Island on the 3rd October (by Catherina Onezia). This is the 35th record for Seychelles.
Ferruginous Duck (Aythya nyroca) – One adult male at the pig farm, Denis Island 25-27 November 2008 (by France Hoareau and John Nevill). This is the 4th record for Seychelles.
Eurasian Hobby (Falco subbuteo) – At least one and up to three at the airstrip and over the coast 24-27 November (by Mickey Mason, Catherina Onezia and John Nevill). This is the 20th record for Seychelles, all from late October to early January.
Yellow Wagtail (Motacilla flava) – One adult male, probably race beema at the pig farm, Denis Island on 9 December 2008 (by John Nevill and Anne-Marie McDevitt). This is the 29th record for Seychelles, reports spread fairly evenly through the months of October to May.

Of course to get a record accepted it is a great help to have photographic evidence! Thanks to the wonders of modern digital photography this is becoming increasingly possible – see sidebar for photos of the species in question.

The records of the major influx of Amur Falcons (Falco amurensis) to Denis in November of last year have also contributed (amongst many others) to the species now being recognised as an annual migrant to the archipelago. There is an interesting summary of records, pertaining to the mass influx last November, from all over the archipelago to be found on the SBRC website. Simply click on the link below to go direct to the summary:

http://www.stokecoll.ac.uk/sbrc/latest/amur%20falcons.pdf

SMR News 7: A population status review…

2009-03-23T03:24:00.000-07:00

On the 25th of June 2008 20 Magpie robins were flown to Denis on a chartered Twin Otter. 16 of the birds came from Fregate and 4 from the island of Cousin[1]. Translocation is a highly stressful experience for the birds and fatalities are not unexpected. The birds all arrived in apparently good condition however including the four from Cousin, which had experienced a sea crossing from Cousin to Praslin that morning prior to their flight to Denis.

A soft introduction method was utilised with the birds being kept by pairs in aviaries that were positioned in appropriately wooded and tranquil locations around the island. Veterinary expertise was on hand courtesy of the Durrell Wildlife Trust as Jersey Zoo, UK. The birds were released on a staggered schedule 2-3 weeks after arrival. Sadly one bird was lost whilst in captivity, a young female, that succumbed to a lung infection the type of which is linked to lowered immune response due to stress – i.e. most likely a casualty of the introduction process.

The released birds however, settled in very quickly, territories were soon formed and males could be heard singing from strategic vantage points high up in the casuarina trees.
Since their arrival the birds have received individual and dedicated care from Catherina Onezia, the GIF Project Officer. Catherina checks on the condition and activities of the birds and provides each territory with a special supplementary food mix 3 times-a-day.

The first egg was recorded on the 4th August and it hatched the on the 23rd! A fantastic start! Unfortunately the chick was later found dead below its nest possibly the victim of a Mynah bird attack.

By the end of December (i.e. 6 months after introduction) there had been a total of 13 nesting attempts recorded. 9 attempts failed:1 pullus was lost (as mentioned above) 2 nests were destroyed by Mynah birds the others failed at the nest building or egg stage. 4 were successful but two of the fledglings were lost – one due to an apparent abnormality with its legs and the other to unknown causes. So by the end of the year the islands population stood at 21 birds – an overall increase of 1. Compared to some past introductions elsewhere this was a very good beginning as a few birds can be lost in the early stages of an introduction before the population stabilises.

The number of nesting attempts is very encouraging and shows that the birds are in good condition and finding the habitat on the island suitable, but the number of failures in breeding is a cause for concern and certainly we need to investigate ways of improving the success rate. I have covered in detail (in my posts of 17th February and 17th March) the issues we are facing with the Indian Mynahs and how evidence is growing that they may be the main problem.

Catherina eventually had to take the injured chick (from the 17th February post) into fulltime care but the bird prospered there and has subsequently been released as an independent bird – the second chick Catherina has successful raised by hand!

At time of writing the island population now stands at 22 birds, including the loss of an adult to unknown causes, so there has been some additional breeding success this year. Let’s hope that we have turned a corner and that 2009 will be year of steady population growth! Keep checking back for updates…

[1] The SMR introduction was the result of a multi-partner cooperation in a project led by Nature Seychelles, supported by SMART (The Seychelles Magpie Robin Recovery Team – a multi-partner initiative) and in particular Fregate Island Limited.

Eurasian Hobby (Falco subbuteo)

2009-03-20T00:38:00.000-07:00

Regular readers will recall in November that the island experienced an amazing influx of migratory birds. Denis played host to some 500 blue-cheeked bee eaters and 40 or 50 Amur falcons and 2 or 3 specimens of a larger bird of prey that at the time I was not able to properly identify though they were suspected to be Eurasian hobbies. I had taken a lot of photos and in December had the opportunity to go through them with Adrian Skerrett of the Seychelles Bird Record Committee (see link to SBRC website in sidebar). A couple of the photos were sufficiently good to be able to confirm the presence of Eurasian hobbies amongst the influx of Amurs.

It also answered the question that had arisen about the predation of bee eaters and a turtle dove that was reported during this period on the island. Amur Falcons, although recorded on occasion to take small birds, typically take insects and small vertebrates like lizards. I observed such behaviour repeatedly with birds swooping down on to the runway and capturing small prey. For the falcons to be taking bee eaters and the significantly larger turtle dove seemed surprising. Eurasian hobbies however are known bird predators and the one instance I was able to photograph of a raptor with a freshly killed bee eater was indeed a Eurasian hobby.

The Indian Mynah (Acridotheres tristis) – a growing problem…

2009-03-17T00:30:00.000-07:00

In my post of February 17th I recorded that a Magpie robin chick had been attacked in its nest by four Mynah birds working in unison! The male did his best to defend the chick but it was this territory that had lost the female only a day or two before. As such the male was alone and whilst he fought with two birds the other two swooped on the nest to attack the chick! The chick was saved by the intervention of Catherina who fortunately was working in the territory at the time and ultimately she has taken it into her care in order to raise it by hand. This kind of cooperation between the mynahs speaks to their high intelligence. I recall in the mid-nineties seeing four mynahs working together on Cousine island to drive a Fairy tern (Gygis alba) from its egg which they then promptly broke and consumed.

The mynah bird appears to be the main problem that faces the magpie robins on Denis with at least two other nests known to have been destroyed by mynahs and at least one chick fatality that suggested mynah involvement.

The Indian or Common Mynah (Acridotheres tristis) is an introduced or Invasive Alien Species (IAS) to Seychelles. Its native range is central and southern Asia and it is widely distributed throughout the Indian subcontinent. It is believed to have been introduced to Seychelles via Mauritius in the late 18th century either as caged bird or possibly as an early and misguided attempt to control crop pests.

The mynah is a highly intelligent and adaptable bird and exploits all terrestrial habitats in the central archipelago from reef flats exposed at low tide to the highest peaks. Though predominantly a ground feeder, the mynah is able to exploit diverse local and temporary food sources. In Seychelles they have been identified as competitors with (for nest sites and food) and/or predators of (chicks and eggs) threatened endemic land birds such as the magpie-robin, Seychelles white-eye (Zosterops modesta) and Seychelles Scops owl (Otus insularis).

Since its introduction the species has spread progressively throughout the central archipelago. Its date of arrival on Denis is not clear but was sometime in the 20th Century as Fryer did not record the bird on the island in either of his visits (1905, 1908) but Stoddart did record it as present during his visit in 1977. Today at a very rough estimate there are some 300 – 400 mynahs on Denis. They can be best seen in the late afternoon feeding on the runway when as many as 150 birds may be seen at one time spread across the entire length of the strip.

The problem now is how do we go about controlling the mynah population? This is far from easy for various reasons. The mynah population has been controlled in the past on Denis using poison. This was done in 2002 in tandem with the rat eradication project that year. The birds were habituated to being fed in a certain location over a period of several days and then the food source was poisoned. This was very effective but was only possible at that time because the island had no rare native birds. Today particularly with the Magpie robin and Fody (and to a lesser extent the Warbler and Flycatcher) we cannot risk using poison for fear of killing one of these rare birds either by direct or secondary exposure to poison. The other options are trapping or shooting but these too bring difficulties.

Traps cannot be left unattended as again non-target species may be caught; as such trapping methods used must be i). ones that do not inflict injury or harm in the process of capture, and ii). must be permanently manned such that non-target birds can be promptly released; and again the mynah’s extraordinary intelligence also comes into play. Whilst working on Cousine Island in the 90’s I instituted a bounty system on the island such that staff were paid SR100 for each mynah they caught. SR100 was worth a lot more then than it is today and consequently staff devoted quite a lot of time and effort to the capture of the birds. In particular I recall Mme. Juliana Souffe catching birds using a simple walk-in pull-string trap that she baited with open papaya fruit. She set the trap up across a track from the kitchen where she spent several hours a day and when a bird went in she simply pulled the string and bagged a bird! After initial success however this method ceased to work. The birds worked out the link of the string to the trap – so Juliana changed the string to a transparent nylon fishing line and latterly buried it from the trap under the sand but the birds still worked it out. What was particularly alarming however was that birds did not just learn to avoid the trap and resist the temptation of the mouth-watering fruit inside – an adaption that one could perhaps expect. Rather they worked out that the string and not the trap was the dangerous item… so they would happily enter a trap which had no line attached and feast on the papaya but would not enter a trap which had a line attached…. now that is frighteningly intelligent!!!

Shooting poses other problems. Firstly it can be very difficult to get permission for a firearm, even an air rifle; secondly the mynahs work it out!! On Cousine we got permission for an air rifle in 1995 and initially were able to shoot a few mynahs. Then however after awhile if you walked around with the rifle you never saw a mynah, but when you didn’t have the gun you saw them everywhere! In other words they had associated the gun with the danger rather than just the human! We could of course seek help from the military or a police unit to get a marksman over with a 2.2 rifle but such activity is not compatible with a hotel resort in full operation – so what to do?

We have actually identified a company in Australia that makes a specialised mynah trap which has certain features which are supposed to overcome the wits of these brainy birds. So I have asked the island owners to order a couple so we can try them out. Let’s hope we can get them in the not too distant future and that they may prove effective in gradually getting the mynah population under control!

Denis Island’s environmental work gets global media exposure…

2009-03-13T03:03:00.000-07:00

In my post of 17th November 2008 I wrote about the filming of our environmental projects by Seychelles National TV company the SBC. This was subsequently aired and I gave links to the footage on YouTube in my post of 12th January.

The work however did not end there. Srdjana Janosevic who led the filming on Denis submitted the footage to CNN’s World Report programme and an edited version appeared for several days on that global network over the weekend before last. It is fantastic for Denis and GIF to receive such global coverage and really puts a massive tick in the Outreach Programme Box under the island’s Environmental Management Plan.

Our sincere thanks go to Srdjana for her interest in our work and her endeavours in getting the images out to the widest possible audience. Indeed we hope to get her back out to the island in the coming months to film another of our projects.

You can connect to the CNN coverage by following the link below:

http://www.cnn.com/video/#/video/international/2009/03/02/wr.feb.28.bk.b.cnn

Also simply click on the images below to enlarge the stills from the footage.

A Unique Morning on a Unique Island…

2009-03-11T00:16:00.000-07:00

The last weekend that I was on Denis - I took the opportunity on the Saturday morning to go round and check on various aspects of ongoing works. I nearly always take the same route when I do this starting in the Old Settlement in the northwest of the island and then basically going clockwise round the island through the various areas and habitats.

That Morning, having just checked the tree nursery, I encountered one of the male magpie robins in the garden of the estate manager it was busy hunting out insects in the grass and then was kind enough to take a nice photogenic perch which I took advantage of.

About 10 minutes later in the northern estate woodland I encountered a male Seychelles Fody in breeding colour (see post of February 19th below) and it also obliged me with a photo-opportunity.

Having gone through the workshops and generator house area, I progressed on to the “farm” where the pig sties, cattle shed and solid waste incinerator are situated. I then headed south towards the runway with the intention of going down the east coast through Belle Etoile. Before reaching the runway however I heard the distinctive call of a Seychelles Paradise flycatcher high up in the Indian almond canopy. It’s a beautiful clear call which catches the attention it being a still recent addition to the island’s birdsong. The bird was 50 or 60ft up and that coupled with the dappled light made getting a decent photo difficult. The bird was however very responsive to being “whistled in” and tantalised me with the hope of a better shot for some 20 minutes before I gave up. During this time I also briefly saw the female. It was fantastic to see a territorial pair of this critically endangered bird seemingly content in their new home on Denis and offering hope of a brighter future for the species.

About an hour later I was well down in the south of the island heading towards the southern promontory when I heard the familiar “chit” alarm call of a Seychelles warbler. I whistled back and the male soon came down into a nearby young papaya tree to call in response and another photo was taken.

I went on that morning to see a grey heron, a beautiful flock of crested terns and a group display of Madagascar fodies – all in a morning’s walk around Denis!

It was not until I went through the photos the next week however that I realised the significance of that morning. Denis is the only island in the world where one can see the “endangered*” Seychelles magpie robin, the “near threatened*” Seychelles fody, the “critically endangered*” Seychelles paradise flycatcher and the “vulnerable*” Seychelles warbler! Nowhere else harbours this combination of rare endemic species and what makes it all the more remarkable is that all four species have been introduced by man to the island since 2004!

This has all been made possible by the investment of the island owners beginning with cat and rat eradication in 2000 and 2002 respectively. What more evidence is needed to show the importance of private sector investment or the benefit that such investment can bring?

*: Classifications as per the IUCN Red List of Threatened Species.

Breakfast on Denis…

2009-02-23T04:03:00.000-08:00

GIF is working with Denis Island to provide an ecotourism product to guests including evening presentations, guided walks, the development of an information centre, pamphlets etc… The wildlife on Denis however is abundant and one does not necessarily have to go looking for it; you can also choose a comfortable location and let it come to you.

A prime example is in the hotel gardens around the restaurant. When the main hotel complex was rebuilt at the end of 2006 the restaurant was extended westwards with a covered decking area that projects out into the gardens. Those choosing to sit there for breakfast, find themselves surrounded on three sides by the natural beauty and wildlife of Denis Island.

Looking North: guests will see flocks of birds feeding on bread put out on the ground by the restaurant staff – typically there will be large numbers of Madagascar fody, Seychelles turtle dove and barred ground dove; 5 or 6 moorhens, mynah birds and the occasional endemic Seychelles fody in a busy whirl of feathered activity. Despite this distraction as the number of clients at table increases some of the Madagascar fodies will take up position on the decking rails in the hope of a titbit from the guests. The few Seychelles fodies that attend take a different approach – perched on the back of a chair across the table from a guest they will, in the manner of a pet dog, fix a diner with an unyielding stare until such time as the induced “mind control” or simple guilt results in the provision of a few choice morsels!

Looking West: the coastal casuarina trees and the veloutier serve to frame and provide vistas of the sea. In the foreground there is a stand of beautiful cordia trees that give shade and provide perches for various birds. There is currently a fairy tern incubating an egg in full view of diners. The egg is on an interesting perch that the bird can not fly directly to. Rather it has to land further down the branch and then climb, through a combination of flapping and sidling, up the branch before carefully lowering itself once more upon the egg. All the birds mentioned above utilise these trees including the moorhens that I have seen well up in the branches on several occasions. The trees also form part of the territory of a pair of endemic Seychelles warblers which can be seen, by the more observant, from time to time gleaning insects from the cordia leaves.

The view south is more open taking in a small garden area with young Guettarda and Casuarina trees. Beyond that lies the hotel’s pool and surrounding decked area and then large veloutier and smaller Bay cedar bushes in an idyllic island holiday scene. The endemic blue pigeon is a common sight in the veloutier bushes feeding on the white berries they produce. The birds thus occupied are particularly indifferent to human attention and make for good photographic subjects.

The airspace in view forms a busy flight path in particular for White terns often in groups of 2 or 3 undertaking their characteristic swooping aerial displays. White-tailed tropicbirds often also pass by amongst others and in November when the island was visited by 500-plus bee-eaters the air was alive with their hawking flights and trilling call as they hunted their insect prey in flashes of colour from dozens of perches.

Every morning is different whether in terms of the breeze, the colour of the sea, the quality of the light or of course the attendant wildlife; and all over a delicious breakfast and a leisurely coffee!

What do you think - worth a visit?

The Moorhen (Gallinula chloropus)

2009-02-20T22:23:00.000-08:00

A common sight on Denis today is the Moorhen (Gallinula chloropus). This species will be familiar to most readers (see photos in sidebar) as it has a wide global distribution. It is native to Seychelles and Denis – Fryer recorded the species present on Denis in 1905 and Stoddart described them as common around the marshy areas on the island in 1977. I don’t recall seeing them when I visited Denis in 1998 but Hill (2002) recorded their presence.

When I commenced regular visits to Denis in December 2005, as part of my current work, moorhens were an uncommon sight on the island. In fact it would be more accurate to state that they were not commonly heard and rarely seen. The last 3 years however have seen an explosion of the population with birds and their chicks a common sight all round the island. They are of course very appealing to the guests around the hotel but numbers have reached such a level that they are now considered a pest around the vegetable gardens and hydroponic tunnels as they like to eat the new buds and impact upon production. Concern has also been raised in some quarters that they may be an aggressive competitor to the Seychelles magpie robin, as both are ground feeders, though as yet there is no substantive evidence to support this.

The reason for the population explosion is doubtless directly related to the removal of alien predators from the island, cats in 2000 and rats in 2002, as the moorhen being a ground nesting bird is particularly prone to their attentions. I observed a similar population explosion on Cousine Island in the past. When I started working there in 1993 moorhens were scarce and very timid with perhaps only 3-4 on the island. It soon became apparent that the birds were timid because they were on occasion still trapped for food by workers on the island. We stopped this practice and then (perhaps also linked with the eradication of feral chickens, construction of various ponds and emplacement of standpipes around the island) over the next couple of years the population on the island rocketed. I ringed a lot of birds at the time and monitored the population. As the numbers increased conflicts between neighbouring territories became common place with regular fighting and several observed incidents of infanticide where adults would raid the neighbouring territory and kill the chicks there!

Later as presumably all available territories were occupied we had periodic spates of emigration when whole generations of sub-adults would leave the island apparently en masse. We received confirmed records of birds I had ringed turning up on Cousin and Praslin as well as anecdotal sightings of ringed moorhens as far away as Fregate and Mahe!

Inter-territory fights are starting to become more commonplace now on Denis also and they can be quite vicious and prolonged. I was able to take a few photos of a fight last week and though blurred, they nevertheless communicate the intensity of the conflict quite well (see sidebar).

I have not ringed any Moorhens on Denis – too many other more important issues to follow – so it will be harder to assess but I expect we may soon have groups of sub-adults exiting the island in search of new homes. It may be worthwhile to contact our nearest neighbours on Bird and Aride islands and ask them to keep a look out for sudden influxes of birds.

Seychelles and Madagascar Fodies

2009-02-19T00:18:00.000-08:00

On Saturday morning I was undertaking my usual duties round the island when I encountered and was able to photo a male Seychelles Fody in woodland north of the runway. The bird was notable because it was in full breeding colour i.e. with yellow feathers on the forehead and beneath the bill. This is the first bird I recall seeing on Denis in breeding colours.

The Seychelles fody (Foudia Sechellarum) is endemic to the central Seychelles archipelago. Believed to have originally occurred throughout the Praslin Group of islands by the mid-20th century it was confined to 3 small populations on the islands of Fregate, Cousin and Cousine – the decline believed to be linked to predation by rats. In 1965, 5 birds were introduced to D’Arros where they have prospered remarkably. Birds have subsequently been introduced to Aride in 2001 and Denis in 2004. The population of Denis has established with evidence of breeding and population growth. The introduction to Denis contributed to the downgrading of the species’ IUCN redlist status from vulnerable to near threatened in 2006 with the global population now estimated at some 3,500 birds spread between the six populations.

Later that same morning on the southeast coast of the island I encountered a flock of Madagascar Fodies (Foudia madagascariensis) in a stand of young papaya plants. What caught my attention initially was the presence of 4 or 5 males in full breeding colour in adjacent plants. Normally males will defend an area from a prominent perch and chase off other males from their breeding territory but in this case they were not. Rather they were busy displaying to a flock of females that were also in amongst the young papaya plants. The Madagascar fody equivalent of going to the Mall or in the Seychelles context hanging around outside “Codevar” I suppose!!! I was able to photo a couple of the males whose bright red plumage so catches the eye.

The Madagascar fody is generally considered to be introduced, although this has been questioned, and is now one of the most common birds in the central archipelago having reached all islands of any size. The Madagascar species does not appear to represent a threat to the local species with populations coexisting on all islands where the Seychelles fody occurs.

Seychelles Magpie Robin – Emergency Management

2009-02-17T03:24:00.000-08:00

I received a call from Catherina on Tuesday 10th with bad news that an adult magpie-robin had been found dead on the island - worse still it was a female. Catherina packaged up the bird and sent it down on the flight so that I could take it to our partners in the SMR work, Nature Seychelles, for furtherance for post-mortem.

Then Wednesday evening more bad news – an SMR chick had been injured by Mynah birds. As it turns out this chick was the offspring of the dead female and was now only left with male to feed it etc… this he was doing. When four Mynah birds teamed up, however, in an attempt to predate the chick in the nest the male was outnumbered and whilst he fought valiantly with two Mynahs on the ground another flew to the nest and attacked the chick. Fortunately Catherina was in attendance and she was able to get to the nest and scare the Mynah away but not before the chick had suffered several injuries. Catherina took the bird into care, cleaned its injuries and applied terramycin before returning it to the territory. She placed the bird on a perch hidden in the roots of fallen tree as she felt the nest location had been compromised. The chick began calling when replaced and the male soon located and continued to tend to it (just going to show how tough and adaptable SMRs really are!).

The next day when Catherina checked on the bird, however, whilst it seemed ok she noted that its injuries had attracted flies which had laid eggs around the wounds. She cleaned them off; but this was soon repeated and so she called me that Wednesday evening to see if I could bring some suitable medicine. It was late so nothing could be done that night and I was due to travel to Denis the next morning so time would be tight.

At 08:00hrs the next morning I contacted Denis Matatiken (Director General of the Nature Conservation Division) in the Department of Environment (DoE) explained to hi the situation to him and asked if he could organise something from the Government vet. Unfortunately it wasn’t possible to get the medicines to me before the flight took off that morning but they were put on Friday morning’s flight. Two ointments and detailed instructions were received and were proving successful in deterring flies when I left the island on Saturday. Our thanks go to Denis, Wilna Accouche and Majella Athanase of the DoE and the Veterinary Department for their help in this regard.

On the Thursday, I observed and photo’d (see sidebar) Catherina cleaning the fly eggs off the chick and also assisted with the reapplication of Terramycin. Apart from its injuries which were healing the chick looked very well and also readily begged for and took the insects that Catherina offered it. I was struck by how comfortable the chick appeared in Catherina’s hands only lightly struggling when she turned it on its back to clean its stomach plumage. Catherina is dedicated to the birds and clearly has an instinctive empathy for the animals that the birds seem able to detect. Catherina then returned the bird to its perch and also rigged a plastic roof for it in case of rain that night. Whilst we were at Catherina’s place we received a visit from “Charlie” the robin that Catherina raised by hand last year who looked in excellent condition.

Catherina will monitor the chick closely over the coming days and if necessary take the bird into captivity as was the case with Charlie, but it is preferable if at all possible that the bird be raised by its remaining parent in its natal territory.

The rarity of the SMR means that the population on Denis receives individual attention from Catherina. Each bird is important as underlined by the cooperation of various agencies in this emergency management exercise. Let’s hope it bears fruit!
Do check back for updates on the progress of this bird and the Denis population in general.

Nature Watch

2009-02-15T23:55:00.000-08:00

I am just back from a visit to the island and have a lot of topics to cover so hopefully, other work permitting, I will be able to make up for the dearth of posts over the last week or so. It is the rainy season at the moment in the central archipelago and we have been having a lot of precipitation on Mahe over the last few weeks. Denis however being small, isolated and flat does not get as much rain as the mountainous granite islands – but on approaching the island on Thursday it was clear that there had been rain as the island was a lush green colour. Indeed as we landed the clouds opened again and it rained steadily for a couple of hours that afternoon. After that however the weather cleared and was fare for the next couple of days enabling me to get around and catch up on developments.

There has been considerable sand movement since my last visit with the distinct sand promontory known as “Pte Madame Guichard” having now reformed and reaching some 50 metres out off the west coast of the island.

As I mentioned the vegetation on the island has benefitted from the rain but Belle Etoile (the cattle meadow on the east coast) has been transformed. A couple of months back I noted how it was brown and all the vegetation had died back revealing the actual lie of the land. Well the grass is once more knee high and upwards, the tortoise tree coppices are in full leaf and many of the saplings planted for coastal rehabilitation which were looking doubtful last year are showing signs of new vigour!

Moving further south I went to check on the tropicbird chick “T2” ground nest to find the bird has fledged. On checking with island staff I was advised it had successfully fledged the week before – so that now makes two successful fledglings from 3 ground nests – a most encouraging start!

Continuing south to the southern point I emerged on the beach to see a heron perched on the southern rocks. It’s unusual to see herons on the island and the light was very bright in effect silhouetting the bird such that I couldn’t really determine its plumage colour. I took a few photos from a distance in the hope that I may be able to discern more detail once they were transferred to the computer screen and then slowly made my way forward. The heron was however vary wary of my presence and before I could move any significant distance closer it took flight eastwards before arcing north and west out of sight up the coast. I was still not sure of its species and so decided to pursue it assuming it would head for the rock promontory on the east coast at Belle Etoile which would provide it with a safe perch surrounded as it is on three sides by the sea.

However as I turned to head back my eye was a caught by a familiar silhouette perched at the top of a casuarina sapling – it was a Bee eater. There are a few still on the island from the mass invasion we experienced in November (See post of 29th November 2008) and Catherina has subsequently told me that the island received another influx of 20 or so birds at the beginning of the month. I took a few shots of it before heading north up the coast in pursuit of the heron. I followed the coast initially but as I reached the Belle Etoile meadows I cut back in land so as to obscure my approach with the vegetation. When I got there however, I was disappointed to find the bird was not where I had anticipated and thinking it had likely flown further north decided to resume my previous path. As I turned to head south once more I saw it, its head bobbing up from behind a sandstone outcrop further south – it was observing me not vice versa!!!

Clearly this bird was very wary and knew of my presence so I cut back in land and tried to approach through some thicker vegetation. Again the bird was smarter than me and was looking directly at me when I emerged from my supposedly hidden route! I took a few more photos from some considerable distance and then accepting defeat left the bird in peace.

On getting back to Mahe I have looked carefully at the photos and magnified them using the usual software. It is a grey heron (Ardea cinerea) it looks like a sub-adult with not all the adult plumage developed; with for example only the beginnings of the black plumes on its head and its legs still a grey colour. This is my first record of a grey heron on Denis, though I am sure they must visit from time to time, but interestingly the timidity of this bird distinguishes it from the very bold birds found on Mahe and suggests that it is just passing through and normally frequents more tranquil parts or alternatively a place where it has reason to fear man.

Migratory Birds.

2009-02-04T23:31:00.000-08:00

Work has kept me away from the island of late and likely will for awhile yet. I do however have various notes from December still to recount. It is now of course the peak of winter in the northern hemisphere and the island continues to play host to various migrants and vagrants.

On the 26th November whilst doing a turtle check I observed a very large flock of whimbrels (Numenius phaeopus) on the reef flats off the north east coast of the island. I had never seen such a large aggregation so attempted to count them. There are of course difficulties in counting a large number of birds as they tend not to stand still whilst you’re counting! I did 3 counts stopping each time when I could no longer keep track of the birds following their movement and my minimum total was 105 while I estimate there were approximately 115 birds in the flock!

Anne-Marie made some very interesting and new records for Denis over December, underlining the importance of an experienced eye:

5th December: 1 Curlew (Numenius arquata) amongst the whimbrels at Belle Etoile.
6th December: 2 white wagtails (Motacilla alba) at the pig farm.
9th December: 2 Lesser sand plovers (Charadrius mongolus) at Belle Etoile.
10th December: 2 Red-throated pipits (Anthus cervinus), one of which was a male in full colour, at the west end of the runway.

On the 9th of December Anne-Marie and I spotted and were able to photograph a Yellow wagtail (Motacilla flava) at the pig farm (see sidebar).

Finally in early January, island resident RMM spotted and photo’d a small tern on and around the coast of the island. it was either a Little or Saunders tern but these are hard to differentiate so he sought assistance from Adrian Skerrett of the Seychelles Bird Record Committee (SBRC) – see link in side bar.

Adrian replied that it was almost certainly a Saunders’ tern (Sternula saundersi)

“...Birds in non-breeding plumage are extremely difficult to tell apart just from photos, but we know from the first birds arriving in Seychelles in September and the last ones leaving in April in breeding plumage that they are almost always Saunders’. In fact we have only once confirmed Little Tern. Features pointing to Saunders in the photos were:
1. The primaries of Saunders Tern have black shafts and Little Tern white. No white was discernible in the pictures, but it could possibly be hidden. If ever you find a dead bird, check this feature.
2. The extent of the black in the primaries is greater in Saunders’. The photos appeared to show extensive black but this is difficult to judge without a comparison.
3. Saunders’ Tern is uniform above whereas Little Tern has a contrasting white rump. This feature is obvious in breeding birds but less so in non-breeding. However the photos certainly appeared to show very uniform upperparts pointing to Saunders’.

Basically I would say it’s 99% certain to be Saunders’.”

5000 hits

2009-01-28T08:16:00.000-08:00

If readership follows the norm – sometime over the next 24-36 hours the hits counter for this blog will register 5000 which is a very pleasing landmark.

A combination of the lack of posts through December and of course the festive season did however see a real drop in readership last month and as yet it has not recovered to pre-December rates. I do of course hope it will pick up again in the coming weeks as awareness of the reactivation of the blog spreads. Nevertheless I would welcome feedback from readers as to how the blog could be made more interesting or useful.

The blog was established to serve two primary purposes:

1). To provide a portal to information on the island’s projects to guests. The Hotel on Denis enjoys a high rate of return clientele, in the region of twice the national average, with many guests returning year after year. Such visitors feel a special attachment to the island and many had expressed an interest in following up on our environmental work on the island between visits. Others, meanwhile, expressed an interest in following a specific project after their visit – the Sooty tern project in particular seems to have been effective in capturing people’s imagination.

2). To function as one means, amongst others, of fulfilling broader awareness objectives in line with the Outreach Programme of the Island’s 5-year Environmental Management Plan (2008 – 2012) - i.e. raising public and stakeholder awareness of the work being undertaken on Denis and its ramifications; whilst also enabling a degree of transparency with regard to these activities.

I have and do receive e-mails from various far-flung places around the planet commenting on the blog and locally I receive quite a bit of feedback from colleagues and stakeholders. The interactive potential of the blog still remains largely unrealised however. At the foot of each post there is a comments tab (i.e. the word “comments” in green) which by simply clicking on you can leave a comment, ask a question make a suggestion etc… and have it posted on the blog. (Now the barrier here is if you don’t have a Google account. Though very easy to obtain, I recognise this will prevent any technophobe from commenting. For such readers please feel free to e-mail me on: office@gif.sc ).

I would very much welcome feedback from readers via this means (or e-mail) about the blog and in particular any suggestions as to how they feel the blog could be improved to better fulfil its objectives.

Thanks JN.

Denis Island 2008 Environmental Highlights covered in National Press.

2009-01-26T03:10:00.000-08:00

2008, as recorded on this blog, has been a remarkable year for Denis Island in terms of environmental progress. I consequently submitted a summary of some of the highlights of the year to the “Nation” newspaper and was delighted to find it reproduced today (26th January 2009) as a full-page spread.

Simply click on the image (left) to read the article or alternatively use the link below to see the article (and photos in colour) on the Nation website:

http://www.nation.sc/index.php?art=14778

Support from Overseas.

2009-01-26T02:32:00.000-08:00

Green Islands Foundation work on Denis Island has been recognised by Belgian specialist pet food company Versele-Laga.

GIF Environmental Officer Catherina Onezia works full-time with the Seychelles magpie robin [SMR] (Copsychus sechellarum) population that was introduced to Denis in June of 2008. The SMR is classified as an endangered species by the IUCN with a global population of approximately only 170 spread over five small populations. Catherina works intensively with the birds checking on their status, well-being and breeding activity. Obviously with such a small global population every individual bird is important and Catherina provides the small sub-population on Denis with individual attention.

A major part of Catherina’s work is the provision of supplementary food to the birds. Each SMR territory has one or more bird feed tables set up and Catherina re-stocks their food supply 3 times a day – once with live insects she has captured around the island and twice with a special bird feed mix that includes grated chicken eggs, bread crumbs, grated carrot or papaya mixed in with a specially balanced high nutrition bird feed and an avian vitamin supplement powder. This feed ensures that the birds are maintained in optimum condition to encourage the breeding activity that is so important in order to properly establish and stabilise the island’s small foundling population. Over the next 3 years the birds will be progressively weaned off this supplementary feed whist at the same time ongoing work continues to improve the quality of the natural habitat on the island.

Versele-Laga produce the special feeds and supplements that we require for the supplementary feed mix. When I placed our order for the two products (Orlux Uni patee and T16 Nutribird pellets) with Versele-Laga however, on hearing of the nature of our work with the Magpie robins they offered to supply our needs for free!!!

We are most grateful to Versele-laga, and in particular their Export Manager Mr Bob Smitz, for their support in our efforts.

Versele-laga is a producer of premium and specialist pet food with more than 40 years experience in this domain. Their website can be accessed via the link below for more details on their products:

http://www.versele-laga.com/NUTRI/Nutrition/Pages/Start/index.jsp

Fairy tern and Tropicbird progress (6): Farewell to Fred and Tina…

2009-01-22T03:52:00.000-08:00

I am still catching up, as pertains to the blog, with various things relating to 2008. One topic which cannot be missed out is the conclusion to the tales of Fred and Tina the Fairy tern and Tropicbird chicks that I have been following on this site since early October (See photographs at the foot of this page).

On arrival on the island on December 9th the first thing I did was go and check on Fred, but his branch was empty. As I mentioned in my post of January 6th below, strong winds at the end of November appear to be responsible for the displacement and subsequent demise of a large number of Fairy tern juveniles around the island. Fred however was quite big and well developed and it occurred to me that he may well be off on a “training flight” with his parents. So I checked his branch a couple of times each day over the next three days but with no luck. Also on the 3rd day I noted two adult terns courting on his branch which seemed to make it all rather final as this species is known to be quick to re-lay following the loss of an egg or young.

Tina however appeared very well, being large and apparently close to fledging (see photo at foot of page). Fledging amongst white-tailed tropicbirds is quite a strange business. The adults feed the chick until it reaches a weight considerably greater than its parents and then abandon it! The juvenile is then driven by growing hunger to make its way to the sea. In Tina’s case this would entail quite a struggle thorough some 40-50 metres of dense undergrowth before she reached the beach and a good opportunity to take flight.

Tina fledged sometime during the 3rd week of December – we wish her well!

I also checked on the second tropicbird chick in its ground nest (named T2) and this was in good condition and growing fast (see sidebar).

Note: I will leave the photos of Fred and Tina through their developmental stages (at the foot of this page) until such time as this post drops off the front page.

Nature Notes

2009-01-16T21:48:00.000-08:00

Made a whistle-stop 24-hour visit to Denis Thursday/Friday this week to take some foreign journalists around the island, this coupled with extended heavy rain during my stay made time for observations very limited. I was however able to make a few notes:

A few blue-cheeked bee eaters remain on the island and I noted two hawking over the runway on Friday morning, I did not see or hear tell of any birds of prey however and it may be that they have now all moved on.
The island has a new batch of moorhen young with new chicks seen with adults at various locations.
Strong winds in late November appear to have resulted in extensive fatalities amongst Fairy tern chicks with a lot of dead birds evident around the island in recent weeks. This is further underlined by a large number of fairy terns now on eggs – the small tree where Fred was raised currently has four adults incubating - suggesting that breeding cycles of pairs may have been synchronised somewhat by these losses.
The Hawksbill turtle nesting season continues apace with the hotel manager telling me that 3 females nested around the hotel restaurant over the festive season.
The Southeast monsoon was blowing strongly whilst I was on the island and aside from bringing the rain it has resulted in considerable beach movement and I will check for erosion issues when I next visit.
All is well with the magpie robin population and now that the flycatchers have started to establish stable territories they too are beginning to form part of the island’s ecotourism product with several guests reporting having seen them on their wanders around the island.

We have a busy period ahead with the hope of finding flycatcher breeding keeping Anselm occupied, Catherina as usual immersed in her magpie robins and preparations for the second season of the sooty tern project imminent. GIF will also soon be starting a new project in the central archipelago and so I will be setting up a new blog to cover our activities elsewhere and will put in a link to it, on this site, in due course!

So keep checking back for updates!

Flycatcher News 1

2009-01-16T03:50:00.000-08:00

As reported, on my post of January 5th, the 25th and 26th November saw the world’s first translocation of Seychelles Paradise Flycatcher. This took place on Denis with the birds being brought over by helicopter from La Digue. A total of 23 birds were transferred (12 males and 11 females) containing a mix of adult and immature birds.

In the days following their release encouraging signs were noted in particular the singing of 3 males suggesting that they were already attempting to establish territories.

Since then the flycatchers have been the full-time occupation of Anselm Barra, Asst Research Officer on the Flycatcher project, who has been monitoring their occurrence, activities and well-being. The information below is the result of his work and covers the first 3 weeks post introduction.

19 birds have been re-sighted and seen on a regular basis.

Initially birds appeared to be setting up territories as early as the day after release, however these territories were often temporary and there was a lot of territory swapping. These initial territories were in the good quality habitat and are still occupied however the birds within them have often changed.
By 3 weeks after release many of the birds had paired up and set up stable territories and are defending their territories against the neighbours. To date 9 territories have established on Denis whilst a few of the birds have yet settle into and are still moving around the island (See Map below 1 of flycatcher territories on Denis in mid-December 2008).

No breeding activity had been observed by mid-December. However very few flycatchers on La Digue had started breeding in mid-December so a lack of breeding activity at this time on Denis is not un-expected.

I will post regular updates on this ground-breaking work so check back regularly for the latest!

The transfer of flycatchers to Denis was enabled by the approval of the La Digue Development Board and is the result of a multi-partner collaboration.

A most encouraging start - nine territories had formed by mid-December!

"Click" on Map to enlarge.

Anne-Marie’s View

2009-01-13T22:02:00.000-08:00

As mentioned in my post of 11th January, Anne-Marie came to our rescue over the festive season and did an excellent job. She has also been kind enough to send a post for the blog regarding her time on the island:

“When an all user e-mail came through Paul Buckley in the RSPB's International Department on Fri 21 November saying that an organisation in the Seychelles was looking for someone to volunteer on a small island for a month, working on the endemic Seychelles Magpie Robin and leaving at short notice, I didn't hesitate.
"Maybe you'd like to think about it over the weekend?" Paul said, but I didn't. I'd worked in Mauritius on pink pigeons 13 years previously and had wanted to visit the Seychelles then, but didn't make it. So, just less than 2 weeks later I arrived in Mahe via London and Paris, opening the plane door to a level of heat that promised to banish the last vestiges of my second winter cold.
I was greeted at the airport by John Nevill, where I had a good update on the project and then it was a short flight to Denis. From the air it looked fabulous, luxurious woodland and aqua fringed white beaches.
On arrival I was met by Catherina who I was to cover for, and because we were due to overlap for just one day, we promptly dropped off my bags and set off on the second round of magpie robin feeding of the day. It was then that I met “Charlie” and little did I know what impact he was to have on my life in the coming weeks! Although I could say that something like love developed between myself and this magpie robin fledgling, reared by Catherina after being found in the nest with feather damage, I did sometimes feel a little tied down, what with the 5.30am wake-up calls and the nightly cockroach collections!
Luckily for me, but not for her, Catherina's stay was extended by another day and so by the time she left I was well versed in how to feed and monitor the robins. With Catherina gone, I spent my first few days settling into the pattern of feeding the robins and constantly marvelling at the wildlife, going 'My God there's a fairy tern, frigatebird, ghost crab, hawksbill turtle, rhinoceros beetle, etc.….. The only downside to report was the mosquitoes, which seemed to have a predeliction for my whiter than white legs! My short sleeved t-shirt and shorts were quickly replaced by a long-sleeved Breton shirt and some XL Denis Island shorts, borrowed from Jean-Jacques!
I am glad to say that the month I was there went slowly and I can honestly say I loved every minute of it. Of course, a lot of this was also to do with the people on the island. Up until 3.30pm each day my time was spent feeding and monitoring the robins, but after a swim, a far cry from the 15 degree water temp in Irish summertime and one of my favourite parts of the day, I would integrate into island life. Warmly welcomed by my neighbours Shane and Jean-Jacques, good friends of Catherina, I quickly got to know a larger group including Maurice and Anselm, Alex at the diving school, Ravish and Robert. From bike mending to snorkelling I was very well looked after and given the cooking skills of Seychellois men, I seriously considered transporting them back to Ireland!
It has taken me a while to register now that I am back home, and at work, but all good things come to an end. I am reassured by Catherina that all the magpie robins previously in my care are in good shape and will be keeping up-to-date on the project through the Denis Island blog, you never know there might be a fledgling named Anne-Marie some day!”

I think it’s the least we can do to name an SMR fledgling after Anne-Marie – although as we name them long before we actually know their gender we may have to change the name to “McDevitt” later on, as bearing in mind the very low global population we can not afford to create any ambiguous birds!

Our sincere thanks go out to Anne-Marie for all her hard work and goodwill in adapting to island life.

Media Coverage

2009-01-12T01:08:00.000-08:00

Public education and awareness, bringing to the broader public attention the important work that Denis Island is supporting, is an important part of GIF’s work on the island. The overall approach is formalised in the “Outreach Programme” of the island’s Environmental Management Plan 2008-2012. Denis has recently received coverage on both the national television channel SBC and in the “Nation” newspaper.

The TV coverage has now been posted on “You Tube” and can be viewed on the following links:

Denis Island Conservation Part 1 http://www.youtube.com/watch?v=PXCg5g2nB4Q

Denis Island Conservation Part 2 http://www.youtube.com/watch?v=xSDfwFJQOY4

Denis Island Conservation Part 3 http://www.youtube.com/watch?v=6ExQD5udL8s

Denis Island Conservation Part 4 http://www.youtube.com/watch?v=XV0VNkzSPeE

Meanwhile the Nation of December 22nd carried a GIF-submitted article on the recent and ground breaking introduction of a population of the critically endangered Seychelles paradise flycatcher (Terpsiphone corvina). Never before translocated this marks an historic moment in the conservation of the species.

Simply click on the image below to read the full article.

Seychelles Magpie Robin News 6.

2009-01-11T23:59:00.000-08:00

The importance of partnership in nature conservation is often cited and the last month in the SMR project on Denis has served to underline this.

Catherina was due to take some leave from the island through December and then at the last minute the proposed replacement fell through! So I contacted Gilles-David Derand the coordinator of the Seychelles Magpie Robin Recovery Team (SMART). He put out a circular e-mail for a volunteer and just in time Anne-Marie McDevitt from RSPB Northern Ireland came to our assistance. Anne-Marie came out to Seychelles at her expense and sacrificed her festive season to work with the magpie-robins – this is dedication!! She took on the dramatic change in climate, the island mosquitoes (which seemed to like her a lot unfortunately) and the rigorous routine that the SMRs demand and all with a cheerful and enthusiastic demeanour. All the information on the SMRs in this update is therefore the result of her work. So our sincere thanks go out to Anne-Marie who is now safely ensconced back in Northern Ireland and hopefully on her way to full recovery from her tropical endeavours.

Feed – Logistical problems are one of the major constraints faced when working on small isolated islands. Now consider that Denis is a small isolated island in a small isolated archipelago and the limitations are further compounded. In December logistical complexities resulted in an imminent shortage of the specialised bird feed we need for the SMR supplementary feeding. Again the SMART network came to the rescue, showing the value of this multi-partner network, in the form of Mr Kevin Joliffe Conservation Manager on Cousine Island. Cousine Island no longer provide supplementary feed for their SMR population and thankfully had a tub left over which filled the gap until our overseas shipment arrived.

So moving onto the birds (see map below for territory status as of 23rd December 2008):

Catherina released the captive SMR juvenile “Charlie” she had raised shortly before her departure. Interestingly Charlie flew back across the runway to Catherina’s place where he had spent the earlier phases of his captivity and was soon taking food from Anne-Marie. Though apparently a little light, Charlie appears well and is foraging successfully as well.

T1 (see map): the fledgling here is progressing well.

T2: the pair here had a new nest at the end of December and appeared to be incubating.

T3: the adults and juvenile are all to be seen feeding at the bird table and look well.

T4: this territory continues to be of concern. Having previously abandoned a breeding attempt the pair built a new nest and laid an egg, this however appeared to be infertile as it did not hatch on schedule and subsequently disappeared - presumably predated.

T5: the chick in this territory was ringed on the 7th December. It possibly fledged on the 13th December but despite frequent observations was not seen. By the 23rd December however the female was seen to be nest building again – a very strong indication that the fledgling has been lost.

Simply "Click" on the map to enlarge!

Other changes are also considerable with affairs of the SMR heart proving fickle (“a la kreol”) once more!

On October 7th I reported (in Bird Bulletin 7) that: i).the female (ringed Orange/Blue) had left her area adjacent to T3 and moved south to pair up with the male in area F (Blue/Red); ii). Whilst the young female (Yellow/Shocking Pink) that had been co-habiting with the pair in area C had moved on. I was hopeful that these moves would see the formation of 9 SMR pairs the optimum possible number for that island at that stage.
Well things didn’t go so well in Area F with Orange/Blue not seen, and assumed floating once more, in that area since late November. This departure caused the male there (Blue/Red) to roam as well presumably looking for the errant female and he was seen in various locations around the island.

The situation has continued to evolve – Orange/Blue has still to be seen since November and Blue/Red has now moved into area C forming a pair bond with the female Black/black and ousting her previous suitor (Sky Blue/New Green) who is now to be seen floating on the periphery of the area.

Meanwhile Yellow/Shocking Pink has indeed re-surfaced in area A with the two males there and it is to be hoped that she will in due course pair with one of them.

So as you can see there is a lot going on and despite some setbacks the population on Denis is slowly increasing with currently 19 adults, 2 juveniles and a fledgling.

Keep checking back for news on this new population of the endangered Seychelles magpie robin.

Invertebrates (1): The Rhinocerous Beetle (Oryctes monoceros)

2009-01-06T23:14:00.000-08:00

Denis Island plays host to some very interesting species of terrestrial invertebrate and insect. During the months of November and December I encountered numerous dead adult specimens of the African rhinocerous beetle (Oryctes monoceros) – so called because of the distinctive horn borne by the male of the species.

Denis was planted from the 1850s onwards as a coconut plantation and it is likely during this time that the beetle which is a pest of coconut trees became established on the island.
Although not as devastating to plantation production as the species that occurs in the Pacific islands, damage by O. Monoceros can be quite severe. Productivity of mature palms can be reduced by adults feeding on the leaf growth points resulting in the characteristic slicing off of leaves. The real damage however is to young palms which can be killed or seriously stunted by continuous attacks. The trunks of dead trees provide the ideal breeding ground for larvae which are very large (See photos in sidebar). On Denis dead logs are often used to demarcate pathways and 10-20 larvae can frequently be found in trunk lengths of only a few feet that exhibit the right degree of decay.

The coconut industry in Seychelles was of significant economic importance in the past and as such the beetle received a lot of attention in terms of measures to control it including attempts in 1949 and 1951 to establish biocontrol in Seychelles through the introduction of the parasitic wasp Scolia ruficornis fabricius. The beetle’s abundance is also related to the abundance of other palm disease agents such as melitomma which influence the amount of dead coconut timber available for rhinoceros beetle larvae. As a consequence one of the best measures to control the beetle is good plantation husbandry.

C. J. Piggot, visiting Denis in 1960 noted:

“Rhinoceros beetle damage is severe but the insect is slowly being brought under control by continued collecting of adults and larvae. It is difficult to discover the main breeding places. There are few fallen palms and no accumulation of decaying organic matter… seems likely they live in manure holes that have been insufficiently covered with sand or soil.”

The economic significance of coconut to Seychelles and the area under plantations today is of course greatly reduced. On Denis despite the recent re-commencement of small scale copra and oil production the coconut coverage is also being reduced as part of the ongoing development of broadleaved woodland habitat for the island’s various conservation programmes such as the introduction of rare endemics like the Seychelles magpie robin and flycatcher. As such I, for one, view the beetle today as an ally in the struggle against the man-made monoculture of coconuts that provides little or no habitat to native species and prevents the re-establishment of native vegetation through the dense undercover generated by sprouting nuts.

Denis Island’s Environment Programmes Enable World Conservation First.

2009-01-05T20:50:00.000-08:00

The Seychelles Paradise Flycatcher (Terpsiphone corvina) is a critically endangered species (IUCN Red List criteria) with the only breeding population restricted to the island of La Digue. La Digue is the 3rd most populated island in the Seychelles archipelago and the related development pressures mean that the long term future of the species habitat there is not secure. Also a species that is restricted to one very small island is inherently vulnerable to stochastic events – such as storms, disease, forest fires etc… and as such it is always important to establish additional populations in order to secure the future of the species.

On the mornings of 25th and 26th of November a total of 23 flycatchers were transferred from La Digue to Denis Island in two helicopter flights. The birds were then transported in their transfer boxes, by buggy, to the largest area of suitable broadleaved woodland habitat on the island. The arrival of a large number of migratory birds of prey (see post of 29th November 2008) in the preceding days was a cause for concern and so it was decided to release the birds at a point 150 metres or so further south from the runway into the forest to lessen the immediate risk of predation.

Each bird was released in turn from its transfer box. Its condition checked by a veterinary specialist and provided with a special re-hydration fluid before release. It was very encouraging to see the good condition exhibited by all the birds on their release.

The birds soon dispersed and by 13:00 hrs on the first day of releases one bird had been seen to fly north across the runway. Over the next two days males were heard to be singing at three separate locations - another very encouraging sign that indicated that birds had identified suitable habitat and were already trying to attract a mate and establish a territory.

This ground breaking introduction, which if successful will represent a turning point for the species, comes as the result of years of work by various partners (see further details at the end of this post):
Denis Island Pty Ltd has of course enabled the transfer by undertaking the rehabilitation of the island’s ecosystem over the last 10 years including the eradication of rats and cats and allowing the conversion of large areas of woodland to suitable habitat types.
Rachel Bristol, the Project Officer, has worked tirelessly over the last two years. On La Digue she has been monitoring the Flycatcher population and working with the local community to advance awareness and to build support for the transfer. On Denis she has been overseeing an 18 month vegetation project to convert approximately 20 hectares of coconut plantation into broadleaved woodland and thereby provide additional habitat in the future for the introduce population to expand into.
The La Digue Development Board (LDDB) – following detailed negotiations and a site visit to Denis to see the available habitat and receive a detailed presentation on the proposed transfer - approved the transfer and signed a Memorandum of Understanding with Denis Island overseeing its terms and conditions.

Following the releases work rapidly switched to the monitoring of birds. Over the next year the birds will be monitored intensively by Anselm Barra and I hope to be able to provide updates on the birds’ progress in the same way that I post periodically on the Seychelles magpie robin population.

This first transfer of the Seychelles Paradise Flycatcher has been a collaborative effort. Donor funding has been received from the UK Darwin Initiative. The overall project leader is Dr Jim Groombridge. Project partners include: Nature Seychelles, the Seychelles Department of Environment, the Durrell Institute of Conservation and Environment, the Royal Society for the Protection of Birds, Wildlife Vets International, RARE UK and the University of Kent.

A New Year

2009-01-05T20:41:00.000-08:00

Sorry for the lack of posts in recent weeks, work commitments and the taking of some annual leave have kept me otherwise occupied. Work and developments have continued apace on Denis, however, with assistance coming from various new partners on our existing projects. I am now back at work and hope to report to you on as much of this in the coming weeks.

2008 was an extraordinary year for the environmental management and conservation on Denis with real breakthroughs of global significance realised thanks to the investment and commitment of Denis Island Development (Pty) Ltd.

Let’s hope that 2009 brings further quantifiable progress and sees the island’s ecosystem advance further on its path of recovery and rehabilitation.

Please do keep checking back on this site for further updates and also feel free to leave comments or seek clarification on issues through the comments tool at the foot of each posting.

Best wishes for 2009,

John Nevill
General Manager
Green Islands Foundation.

Close Encounters of the Feathered Kind (2)

2008-12-08T03:28:00.000-08:00

Back on August 13th I posted on the subject of close (in-hand) encounters with two birds, a Crested tern and a Seychelles warbler, that had their respective problems but thankfully appeared to be ok following a little assistance. During my last visit two more birds were encountered up close

Amur Falcon (Falco amurensis) – as detailed in my post of November 29th the island experienced a large influx of Amur Falcons recently. What I didn’t mention was that one bird was found dead and another in a highly weakened state. Fortunately Dr Alan Greenwood a wildlife veterinary specialist was on the island (as part of another project which I will post on in the coming weeks) and was able to help with the stricken bird. The falcon was weak, a little skinny and doubtless exhausted from its long journey. On closer inspection its wings and tail feathers were also found to be “gummed up” with the silk from a palm spider web which appeared to be preventing it from flying. Alan took the bird into his care and gave it a special re-hydration fluid and then proceeded to feed it with some choice cuts of fresh raw chicken we were able to obtain from the poultry slaughter house. Initially reluctant and uncooperative the falcon soon seemed to realise that it was on to a good deal with Alan and became relaxed in hand and readily took the proffered food until Alan was satisfied that its crop was suitably full. Then, with plumage cleaned of spider’s web, the Falcon was kept in a box and fed several times over the next 48 hours before its release, apparently much better off for the experience!

Ferruginous Duck (Aythya nyroca) – Mr Francois Hoareau the Village Coordinator of the island’s estate called me on 26th November and told me he had found a duck the previous day, picked it up and put it in the poultry farm. I went with Francois to see the duck and immediately saw that it was a Ferruginous duck (also known as a white-eyed Pochard) with the typical white wing bar and white eyes. The ferruginous duck originates predominantly from Eastern Europe through Russia and Mongolia and is an occasional vagrant to Seychelles. Francois had found the bird bathing in a puddle at the pig farm. Clearly the bird was exhausted from its journey as it had offered no resistance when he went to pick it up. I inspected the bird and it seemed in reasonable condition it was not too skinny, plumage was intact and it was now quite lively in the hand doubtless aided by a night’s rest and the readily available feed and water in its pen. We decided to keep the bird in the pen for another night before releasing it the next day.

Fairy Tern and Tropicbird Progress 6

2008-12-01T03:03:00.000-08:00

When I wasn’t looking at Falcons and Bee-eaters I managed on the afternoon of the 24th November to get round and check on the terns and tropicbirds I have been following on the blog over the previous weeks.

Fairy Terns:

The second chick has now left its perch, I checked every day during my stay and didn’t see it. There had been very strong winds the week before (an event doubtless also related to the influx of bee-eaters and Falcons reported in the post below) and it is likely that these drove the bird from its perch which was quite exposed and near the beach. The bird was well-developed however and I am optimistic that it was sufficiently independent to survive.
Fred was still on his perch and has further grown with good plumage development now evident and tail feathers developing. I have added “his” latest photo to the development timeline in the sidebar at the bottom of this page.
Interestingly on an adjacent branch on the same tree another adult Fairy tern has commenced incubation.

Tropicbirds:

Tina is now getting big and her plumage is developing rapidly. She looks very healthy and I have added the latest photo to “her” development timeline at the foot of this page.
The second ground nest is currently not occupied, but the first is and I am delighted to say that it now also has a newly-hatched chick. This is the second confirmed chick in a ground nest following the rat eradication and reaffirms the good progress being made in the island’s ecosystem rehabilitation.

An Extraordinary Day…

2008-11-29T21:07:00.000-08:00

I arrived on Denis early on the afternoon of Monday 24th and on leaving the airport area and heading towards the hotel I immediately became aware of a new and unusual bird call – a high-pitched staccato trill. Looking up I saw several bright green birds stunting and swooping in the air, Bee-eaters were flying everywhere! In truth this was not such a surprise as I had been contacted a few days before by Adrian Skerrett of the Seychelles Birds Record Committee (SBRC - see link in sidebar). Adrian had informed me that several islands in the archipelago had reported an influx of bee-eaters in the preceding days and wanted to know what the status on Denis was. What was surprising was the shear number of them. Every prominent perch on every tree and bush along the path seemed to hold one of these beautiful green creatures and the air in every clearing and break in the canopy was alive with the birds darting and swooping in pursuit of their insect prey. I stopped to watch a bird on its perch, every few seconds it swooped off hawking for an insect before veering round to return once more to its previous vantage point – such activity was repeated on practically every prominent branch along my route.

This in itself was remarkable enough but once at the hotel the resident manager Paul Horner advised me that there were some 50 or more falcons on the island as well!!! To be honest I was rather sceptical that there could possibly so many birds of prey on the island at one time and thought it likely there were maybe half-a-dozen or so birds of prey that in their circling might give the impression of being more numerous. I rapidly revised this opinion on walking down the runway, however, falcons were everywhere it was astonishing and they were equally abundant down the east coast in the area called Belle Etoile - I have never seen anything like it before and 50 birds appeared a fair estimate of their number.

The combination of these occurrences changed the whole ambience of the island and imbued a certain sense of awe to the whole scene. It reminded me of the feeling I used to get during my first year in Seychelles when every few days I would encounter something new, exotic and remarkable – it was an extraordinary day.

Species.

The bee-eater was of the blue-cheeked variety – Blue-cheeked bee-eater (Merops persicus) - which occurs from northern Egypt through the Middle East to Pakistan and India, and overwinters in Africa. It furthermore lived up to its name on Denis cleaning out the hives at the apiary and according to the hotel gardeners decimating the wasp population too!

Birds of Prey, like certain waders, due to the similarity of various species can be rather difficult to identify and this is certainly not my field of expertise – but the falcons were predominantly Amur Falcons (Falco amurensis) as the adult male has very distinctive plumage and once having seen that it made it easier to zero in on the plumage characteristics of the female. The Amur falcon breeds in northeast Asia and migrates to southeast Africa.
There was however at least one other species present with birds being noticeably larger _ I was unable to get a good look at these birds but Catherina and others also saw them and believe they may have been Eurasian hobbies (Falco subbuteo). As I said several species are quite similar and we will be sending photos to the SBRC to try and pin down identifications.

Numbers.

On an island like Denis, quite large and heavily forested, it is very hard to estimate how many land birds there may be. On Monday when I arrived however, the bee-eaters were the most abundant bird in the air in clearings and on walking around the island later, as part of my normal duties, they were also present in considerable numbers round the coast and in particular the east coast and my estimate would have been several hundred (i.e. 3-500 birds). On Tuesday the numbers were significantly reduced and yet that evening there were more than a hundred of the birds hawking over the runway alone! The decline continued over the next two days with a marked reduction each day but even so on my departure around midday on Thursday there must still have been between at least 50 bee-eaters on the island. Furthermore I am told by Catherina and other island residents that the first birds were noted on the afternoon of Wednesday 19th and that by the day of my arrival numbers had already significantly reduced from the peak of Saturday. Putting these observations together would suggest that there were at least 500 bee-eaters on the island over the weekend.

With regard to the Falcons I think 40-50 is a good estimate with the birds concentrated in and around the runway and also down the Belle Etoile (east) coast. I have never seen so many birds of prey together at one time and it was a truly amazing sight! On Tuesday morning Catherina and Paul Horner undertook a count along the runway and encountered 23 birds of prey in just one transect! Numbers declined noticeably from Tuesday to Thursday. The birds were best seen perched along and hunting over the runway. They could hover - almost harrier-like - when facing into the wind and would swoop down onto the runway to take insects and lizards – but also birds! I received several reports of the falcons taking bee-eaters and also a turtle dove. I latterly also saw for myself thanks to the help of an estate staff member a female falcon feeding on a bee-eater.
With regard to the larger bird of prey species, I think there were only 2 or 3 on the island.

News round-up

2008-11-27T23:25:00.000-08:00

(Please note that this post was written Monday the 24th November but due to internet problems is only being posted now).

Sorry for the delay in posting but things have been pretty hectic lately, sadly mostly due to dull, ineffectual committee meetings which one has to attend just in case something important is raised – but of course it generally isn’t!!!

We should, however, have some exciting new developments on Denis in the coming days and I hope very much to be able to report back to you on Denis’ role in a new conservation first sometime next week… so keep checking back.

In the meantime let me just summarise matters from my visit to the island of November 14th-16th which I haven’t reported on yet:

Fairy tern and Tropicbird progress:
Fred and Tina are both progressing well and I have added the latest photos at the foot of the page. The first fairy tern juvenile appears to have finally left its perch which is good, whilst the second now appears adult except for the remnant brown barring on its wings. Only one of the other two tropicbird ground nests is currently occupied but does give the impression it may be incubating.
Shearwater colony:
All appears well at the shearwater colony with the egg I previously reported on still under incubation (see posts of November 7th and October 26th).
SMR update:
Great news that we have a new chick in Territory 1 and also that the juvenile under Catherina’s captive care appears well on the way to recovery which is most encouraging. The new pair that we hoped was forming in the southern portion of the island (see post of October 7th), however, appears to have failed. the female is no longer resident there and the male has been found wandering further afield no doubt in search of the female. The female has not been seen for a few days now but it is assumed that she has resumed floating – so I will keep you up updated on developments.
Migratory birds:
There has been a notable decline in the number of wading birds around the island recently but I did twice see the juvenile Purple heron during my last visit so that is still resident having first been seen on October 3rd (see post of October 5th).

Shells 1 – Trochus virgatus

2008-11-18T23:30:00.000-08:00

In recent weeks I have been undertaking frequent circuits of the island to count turtle tracks. This has also given me the opportunity to note the various species of shells that are washed up at high tide. One of the projects under the island’s biodiversity plan is to survey the marine life on the surrounding reef flats and whilst that activity is not scheduled for another couple of years, identification of shells on the beach is as good a starting point as any.

Of course many of the shells washed up are old or damaged and not of sufficient quality for good photographs to be taken such that readers can readily identify the species in question from the photo on the blog. So in each case I will only post on a species when I encounter a good quality and characteristic shell specimen.

So I start today with Trochus virgatus. The Trochidae are a family of medium to large sea snails with conical shells that typically graze on algae though some eat sponges. T. virgatus is very similar to T. maculatus with one of the key differences being that the columella of maculatus is toothed. Jarrett (2000) states that T. virgatus is common in Seychelles being typically found in secure niches on the open reef.

Simply click on the photos below to enlarge.

(Photos J Nevill 2008).

Jarrett, A.G. (2000): Marine Shells of the Seychelles. Carole Green Publishing, Cambridge, UK. ISBN 1 903479 00 2

National television coverage for environmental work on Denis Island…

2008-11-17T02:19:00.000-08:00

I was not able to undertake my usual routine during my latest visit to Denis – firstly I was rather unceremoniously bumped from the flight going up on Thursday due to the fact that the plane was overloaded!!! So after waiting for my luggage to be offloaded I had to then head back to the office, only to go back out to the airport the next day. Fortunately I was allowed on the Friday flight and hence was able to check on the Fairy tern and Tropicbird chicks we have been following that afternoon.

On Saturday however, there was a morning flight that brought in Ms. Srdjana Janosevic and Mr. Humbert Mellie from the Seychelles Broadcasting Corporation – the national television company. Srdjana had been made aware of this blog by Lena Desaubin (Director of Education, Information and Communications at the Department of Environment) and having read through it was interested to come and film some of the work we are doing on the island for a national TV spot and perhaps also for wider distribution.

So on Saturday morning and afternoon, we went round the island and Humbert took the opportunity to film our “famed” fairy tern and tropicbird chicks “Fred and Tina”, the shearwater colony, some good footage of Magpie robins, good close ups of an adult tropicbird, a sub-adult Brown noddy, Bridled terns etc… later that afternoon they interviewed hotel staff and took more scenic shots round the island.

We were up nice and early on Sunday morning to accompany Catherina on her morning round to provide the magpie robins with their first supplementary feed of the day. We started off at Catherina’s place to film her feeding the captive juvenile under her care and then we headed off. Humbert got some great footage of the robins coming to their feeding stations in three different territories meaning he and Srdjana should be spoilt for choice in the editing room. Catherina was also interviewed about her work and the robins. She then went and checked on a nest in Territory 1 and was able to confirm that the new chick there is progressing well.

We spent the rest of the morning trying to fill in a few gaps with footage of the giant tortoises, the large day gecko, the Seychelles warbler, more shots around the hotel and additional scenery etc…

Srdjana will let me know in due course when the footage will be aired on national TV and will also be posting footage on various internet sites – the links to which I will include on this blog in due course, to enable those who are interested to go and view it. There is also the intention to submit footage to an international carrier/network and likewise I will advise readers on that as and when I hear myself. So keep checking back for information!

Our sincere thanks go to Srdjana, Humbert, Lena and the SBC for showing interest in our work.

SMR update.

2008-11-10T03:59:00.000-08:00

The Seychelles magpie robin is a ground feeding bird, its favoured method of foraging is turning leaf litter and eating the invertebrates concealed beneath, it will however also take young lizards and small fish dropped by seabirds etc… The birds on Denis have been habituated to supplementary feeding on bird tables with special food mix prepared by Catherina. They are also opportunistic however, and often when I encounter a bird on the island I will disturb the leaf litter with my feet over an area of a square metre or two and then move a few yards away. The bird, eyes-a-glitter, rapidly descends and having cocked a sidelong glance at you to make sure you are far enough away for its comfort begins to feast on the exposed invertebrates.

A logistical mishap late Tuesday afternoon left me without a room to change etc.. and whilst I waited at the old settlement north of the runway I saw one of the single males sitting on a branch in a Banyan tree. I kicked up some leaf litter and took the opportunity to take a few photos (see sidebar).

The next morning I went to check on the captive chick which I reported on in my post of November 3rd. As I approached the aviary on Catherina’s veranda the bird was giving repetitive rasping and plaintive call. So, having checked that it had water, I set about trying to find it some food by digging around in the adjacent undergrowth and turning logs etc… Over the next 30 minutes or so I was able to bring it quite a feast of small cockroaches which are amongst their favourite food. When I approached to proffer the food the chick, with its mouth gaping yellow, would begin begging louder and louder reaching a crescendo at the point when it would pluck the cockroach from between my fingers.

I did not take the bird out to examine it or take photos (because they would have necessitated a flash) as I did not want to unduly stress it, but it looked quite healthy and I will follow up with Catherina in due course as to the status of its wing.

Keeping checking back for updates!

Fairy Tern and Tropicbird Progress (5).

2008-11-09T21:56:00.000-08:00

Fred is developing very well with significant growth again to be noted. I will rearrange previous photographs and add them to the bottom of the page so that the progress of Fred and Tina can be followed through time so scroll down for those dated images.

The second juvenile is also developing well with plumage near fully developed and the juvenile barring on its wings fading. The first juvenile however continues to give me cause for concern for although it now appears fully developed I have yet to see it fly from its perch.

The tropicbird adults are still at their nest sites but I have yet to verify whether they are indeed now incubating. Tina however shows considerable growth and has now largely lost her cute fluffy appearance with extensive plumage development now apparent. Again scroll down to the bottom of the page to see the development of Tina through time in dated photographs.

Bird Bulletin 9

2008-11-07T02:17:00.000-08:00

During my most recent visit to Denis (4 – 6 November) I noted some interesting activity and changes in the island’s bird population:

I checked on the shearwater colony and was this time able to get a much better photo of the adult shearwater incubating its egg (see sidebar and also my post of 26th October) and all seems well.
There has been a significant decline over the last week in the number of wading birds on the island. I don’t know why this should be but the number of Whimbrels has dropped dramatically to just a handful and there has been a significant decline in the number of Turnstones. Likewise I noted only one Crab plover, a few Sand plovers, one Ringed plover, one Pratincole and I didn’t see a single Grey plover. This represents a very dramatic change and I can only suggest that it may be linked to the very calm and hot weather we have been experiencing lately.
Furthermore Crested tern numbers have dropped from a record high of 14 over the last few weeks to just 2.
The bridled tern roost also appears to have dispersed though individual birds are still to be seen perched on the mooring buoys during the day.
I noted interesting behaviour amongst the fairy terns that I have not noticed before. It is usual to see fairy terns in pairs or threes in their swooping flight display particularly along the coastline and I have on several occasions in the past observed them in large numbers mobbing a migrant bird of prey. On Tuesday 2nd however I noted between 40 or 50 of them flying together very high up (several hundred feet), circling and tumbling, for about 10 minutes. There was no other bird amongst them – so this was not a mobbing event – something new for this observer.
As an aside I also noted a sub-adult Brown noddy in the hotel garden. It is perched on a low ornamental palm and has clearly fallen out of its nest in a nearby coconut palm. The bird is well-developed with only slight traces of its juvenile plumage still visible, and it is being tended to by its parents so it should be fine. It does however offer an interesting start to the guest nature walks as they do not usually get such a good view of this species.

Nature Watch 3

2008-11-06T22:28:00.001-08:00

Flying in on Tuesday 4th October Denis was picture perfect – there had a been some rain in the preceding week and the foliage showed a fresher green whilst the sea was as still and clear round the island as I have ever seen it. As we circled before final approach over the shoals to the northwest I looked down in the hope of seeing some wildlife in the water The water being so clear I had high expectations but on the approach I was disappointed to only see one turtle surfacing for a breather.

On arrival I made my usual check on the fairy tern juveniles that I have been following over the last couple of months and I will post on that later.

In recent weeks I have been undertaking thorough beach checks each time I visit in order to count turtle tracks (see post of October 22nd). It takes a good couple of hours to walk round the island and it is hard work with the sand very soft and fine in places and trees down blocking the way in others. It is also however a great opportunity to take in the beauty of the island and make various natural history observations.

Walking the beach on Thursday (6th) morning on the southwest beach I noted a turtle close in shore head above the water checking out the beach. It is normal for hawksbills to survey a beach before coming ashore, I assume to assess whether it is safe. The animal only being about 10 metres or so offshore, I hid behind a tree and kept still hoping it may soon emerge to nest. Whilst watching it cruise around in the shallow water my eye was caught by movement further offshore – there was a second animal about 40 metres out also surveying the beach. Over the next 5 minutes I realised there were at least 4 (and I believe 5) hawksbill turtles all within 50-60 metres of the shore all apparently assessing the beach as a suitable nesting site!!! I waited for some 20 minutes convinced that one would emerge at any moment but without luck. The need for me to finish my rounds in time to catch my plane off the island meant I had to move on but I am certain that 2 or more of these animals will have nested soon after.

One frequently encounters hermit crabs on the beach during a turtle track count and as per previous posts (see posts of July 16th and September 10th) recent GIF research has indicated that the populations on the island may be limited by a shortage of suitable shells for the crabs to grow into. Casual observations seem to support this as I encounter very large numbers of small crabs in neritas spp shells etc… but much fewer larger ones in turbo shells. Furthermore many of the larger hermits have clearly outgrown their shells. When a crab fits well into its shell its large chela (claw) and one leg should fill and close the shell aperture, effectively “closing the door” and protecting the animal from attack when it retreats within. I am however frequently finding specimens where several and even all the limbs remain exposed when the crab seeks refuge and this presumably makes the animal much more vulnerable to predation from species such as the crab plover.

Also during my rounds I have been paying closer attention to the old shells washed up at high tide and I have been photographing specimens which are still in reasonable condition to enable species identification and I hope to start making occasional posts on this in the coming weeks.

Check back regularly for further observations, news and updates!

SMR News 5: “Trials and tribulations…”

2008-11-03T03:43:00.000-08:00

Well it seems hard times abound and not just for financial institutions, IMF indebted countries and Joe the plumber!! Not all goes smoothly for the Seychelles magpie robin in paradise either. Well I suppose if it was easy they wouldn’t be endangered…

So in the tried and tested formula, I’ll start with the good news and let it deteriorate from there…

The fledgling from T3 is well and prospering and continues to harass its parents for food.

The pullus from territory 4 (that I reported on as egg in Bird Bulletin 7) fledged on the 13th of October – yes it was a little further advanced than we had appreciated!

On the 24th of October Catherina also observed the female of territory 1 entering a natural cavity in a Casuarina tree suggesting that breeding activity has recommenced there.

SMR TERRITORY MAP AS OF END OF OCTOBER 2008

CLICK ON THIS IMAGE TO ENLARGE.

On the 14th of October however Catherina noted that the new fledgling from T4 was having some difficulties. She captured it to examine it and found that the skin on one wing appeared old and shrivelled and that the feathers there were falling out and breaking (see photos in sidebar). The area was also attracting flies and as we all know there is no fooling them! So Catherina took the bird into captivity and treated the skin with terramycin spray whilst seeking advice from veterinary specialists overseas – via Rachel Bristol of Nature Seychelles.

The primary concern initially of course was that the longer the bird was away from its parents the more likely they would reject it when it was returned. To counter this Catherina returned it frequently, in a small carrying aviary to its territory so that the parents could see and interact with their offspring. Feedback from the vets however ultimately resulted in the recommendation that the bird should be kept in captivity and hand reared. So Catherina has set up a small aviary on her veranda to facilitate the hourly feeding her new dependent requires. To date the bird appears otherwise healthy, but this development is less than encouraging. Of the 4 chicks the island has produced so far the first was lost to a likely Myna bird attack whilst still a nestling, the third appeared to have a physical deformity of its legs and died within a couple of days of fledging and now this the fourth is manifesting other problems. The second fledgling continues to prosper.

Of course, as I have previously stated, juvenile mortality in SMRs is known to be high and it is for that reason we do not count a bird as part of the population until it has reached full independence. Nevertheless it is to be hoped that average success will ultimately exceed 1 in 4 particularly at this crucial formative stage of the new colony where a rapid increase in numbers is so desirable for the future resilience of the population.
Keep checking back for news on our captive chick and the population in general.

Migratory Birds Report 2

2008-10-31T04:40:00.000-07:00

Catherina, I and others are keeping our eyes peeled for migratory birds and so building on my first report (posted on October 5th) and in addition to the normal large numbers of whimbrel and turnstone, we have the following to report.

Ringed Plover (Charadrius hiaticula): a single bird seen in the hotel gardens, and on the east coast reef flats.

Grey Plover (Pluvialis squatarola): total numbers of wading birds of any particular species round the island are very difficult to estimate as the birds are often dispersed around the coast and are of course much more mobile than your average observer. It is clear however we have several grey plovers (5-6) on the island at this time.

Crab Plover (Dromas ardeola): there are at least 2 and possibly as many as 4 of these elegant birds on the island being most commonly seen around Pointe l’Est

Gull-billed tern (Gelochelidon nilotica): During the 9th and 10th of October I observed 1 bird on three separate occasions flying quite low over the coast, twice around Pte Mme Guichard and once on the west coast by the runway.

Catherina has two interesting records of a European turtle dove (Streptopelia picturata) on the 5th of October and a Common pratincole (Glareola pratincola) on the 6th.

Finally Mr Mickey Mason, an island resident, spotted mid-month an unusual visitor along the coast and was able to take some photos from a distance (see sidebar), as per his own description:

“I found a tern last weekend flying over the beach and diving for food amongst weed and debris. It has graceful flight but quite agile, turns sharply to dive and hover above the beach when it has noticed something of interest. Looks like a type of Marsh tern[1]… sorry about the photo quality.”

This information and the photos of the bird have been forwarded to Mr. Adrian Skerrett of the Seychelles Bird Record Committee (see link in sidebar) in the hope that it may be possible to make a verified identification.

[1] (a) Chlidonias hybridus: whiskered or marsh tern; (b) Chlidonias leucopterus: white-winged or marsh tern

Fairy Tern and Tropicbird Progress (4).

2008-10-28T05:39:00.000-07:00

As usual the first thing I checked on arrival on Thursday 23rd was the status of the three fairy tern juveniles that I have been following over the preceding weeks and reporting on in the earlier editions of this post.
• As with two weeks ago the first juvenile looks fully developed except for the lack of the purple colouration at the base of its bill. I am becoming a little concerned however that this bird is always on its perch. I have yet to see it fly and does seem rather passive. Those of you that have followed the earlier posts on this topic will recall that I started these observations because an unusually high number of fairy tern chicks seemed to be dying around the island in the preceding months suggesting perhaps that there was a food shortage. I do hope that this bird is not following that route.
• The second chick that we have followed since hatchling is progressing well. As reported 2 weeks ago it is alert and already flying. Its plumage has further developed in the interim and the juvenile barring on the wings is becoming less prominent.
• Our third chick “Fred” which we have been following since it was an egg(!) is also showing good growth and development, “he” is very alert and has taken to moving up and down his branch. The plumage however is still very much that of a chick.

Moving on to the Tropicbirds I have very encouraging news:
• The first nest site that had been unoccupied during my checks over the last four weeks again has an adult in place – so let’s hope for an egg this time!
• The adult is still present at the second site and I have still been unable to determine if there is an egg being incubated – the single large brick-red egg typically takes some 6 weeks to hatch and is incubated in turn by both parents.
• Tina our chick appears very well, she is alert appears in good condition and has grown significantly such that the first proper juvenile plumage with black barring is now evident (see photo in sidebar).

Check back regularly for further updates on Fred and Tina’s progress.

Shear(water) Delight – Another first for Denis Island!!!

2008-10-26T21:36:00.000-07:00

In previous posts (see August 18th and October 19th) I have written of the re-establishment of a small Wedge-tailed shearwater (Puffinus pacificus) colony on Denis and the significance this has as an indicator of the rehabilitation of the island’s ecosystem since the rat eradication of 2002. As of November 2007, a small colony of burrows was found on the east coast of the island but at that time I was unable to find proof of breeding activity. The shearwater may breed at any time but shows a distinct peak in breeding activity September through February. I have, therefore, been monitoring the burrows closely over the last 4-6 weeks in the hope of finding evidence of breeding and thereby prove the species is indeed once again established on Denis.
So I am very happy to relate that on Thursday 23rd October I found, and was able to photograph (see photos in sidebar), an adult shearwater incubating an egg in one of the burrows!!! This therefore now verifiably proves that the species has established a small breeding colony on the island – yet another exciting landmark for Denis.

Skerrett et al (2001) state of wedge-tailed shearwaters that:

“Sexes share incubation, each shift lasting several days. Incubation usually takes 50-54… and chicks fledge after three months.”

I will continue to keep a close eye on our small colony in the coming weeks and hopefully in due course I will be able to find more eggs and record the subsequent chicks. So keep checking back for updates!

It doesn’t stop there however, Mr Paul Horner the hotel manager, has advised me that in recent days he has twice had call to remove from the hotel restaurant what, as per his description, sounds very much like an Audubon’s shearwater (Puffinus lherminieri); the bird having become confused by the restaurant lights. I have asked him to photograph the bird should the incident reoccur as if it can be confirmed as an Audubon’s this would suggest that this species may also now be roosting on the island!!!

Skerrett et al (2001): Birds of Seychelles. Christopher Helm (publishers) Ltd. London.

The Hawksbill Turtle Season Begins…

2008-10-22T00:04:00.000-07:00

When Denis De Trobriand discovered Denis in 1773 he described turtles as abundant in the waters around the island. Two species of turtle are still to be found nesting on Denis today – if in much reduced numbers from the abundant days of De Trobriand.

The Green turtle (Chelonia mydas) nests on Denis in small numbers year round with a peak of activity in April through June. The Hawksbill turtle (Eretmochelys imbricata) has a much more distinct nesting season (October – February) which is now commencing on Denis.

The hawksbill is classified as critically endangered by the World Conservation Union and Seychelles is one of the best five remaining locations in the world for the species (Meylan & Donnelly 1999).

Threatened by hunting for its shell (known as tortoiseshell) and loss of habitat – most critically nesting habitat – the hawksbill has received full protection under the law in Seychelles since 1994. Despite the success of certain protected area nesting sites the overall population has continued to decline (Mortimer 2004) with loss of nesting habitat to tourism development and activity being considered the primary ongoing problem.

Denis Island is member of the “Turtle Action Group Seychelles” (TAGS) which is a newly-formed association of some 14 agencies that manage turtle rookeries (nesting areas). As a requirement of its membership Denis must collect information on its nesting turtle populations and submit it to a national stakeholder database operated by TAGS. Data has been collected in the past on nesting turtles but limited human capacity has and continues to be the primary constraint to the consistent collection of standardised data. During the peak of the season thorough monitoring on Denis would entail at least two people working full-time. It is hoped that for season commencing in 2009 that designated accommodation will be available on the island to enable basic but thorough data collection to be undertaken by volunteers.

In the meantime however efforts will be made to gather the most basic form of data through the counting of tracks on the beach. Although turtles by no means nest successfully every time they come ashore the body of work by Dr Jeanne Mortimer has enabled a ratio of beachings per nest to be established for the Seychelles hawksbill population and this can be used to estimate the number of females actually nesting on Denis.

I will in due course periodically report on the progress of the season and set this in the context of management measures. This information will help guide management activity on the island and identify issues to be mitigated in order to optimise the breeding success of the hawksbill rookery on Denis. So check back regularly for news on the season as it progresses!

Meylan, A.B. & Donnelly, M. (1999). Status and justification for listing the hawksbill turtle (Eretmochelys imbricata) as Critically Endanagered on the 1996 IUCN Red List of Threatened animals. Chelonian Conserbvation and Biology 3 (2): 200 – 224.
Mortimer, J.A. 2004. Seychelles Marine Ecosystem Management Project (SEYMEMP): Turtle Component. Final Report. Vol 1: Text, 243 pages. Vol 2: Appendix 1-11, 158 pages.

Denis Island turns the corner…

2008-10-19T22:23:00.000-07:00

This blog is one means of publicising the work Denis Island Development (Pty) Limited and GIF are undertaking, on Denis Island. The web is not available to all however and as such we also utilise other media to raise awareness and share information with stakeholders, interested parties and the general public. The article below is published in today’s (October 20th) Seychelles Nation newspaper. I have also posted a photo of the article below – click on this photo to see the article and its images in full size.

Denis Island turns the corner…

Denis Island began its ecosystem restoration programme 10 years ago when it undertook a preliminary alien mammal species assessment. Cats were subsequently eradicated in 2000 and rats in 2002. This is very important as Seychelles naturally has no terrestrial mammals, except for two species of bat, and the fauna and flora of the islands have evolved therefore without the necessary adaptations to cope with the impacts of animals such as rats, cats, pigs and goats. Today Denis represents 17.5% of the rat-free land in the central archipelago and is thus vital to several national conservation initiatives.

Denis Island has embraced stakeholder partnership as a means of furthering its own and national environmental objectives. In 1999-2001 Denis worked with Nature Seychelles to rehabilitate 35 hectares of broadleaved woodland habitat on the island in order to enable the introduction of rare endemic birds. In 2004 the rare Seychelles fody and Seychelles warbler were introduced and monitoring over subsequent years has shown that the populations have established well and are expanding. Then in June of this year, again in partnership with Nature Seychelles, 20 endangered Magpie robins were introduced and here too progress is very encouraging with island’s first fledgling developing well.

In 2006 Denis signed an agreement with the Green Islands Foundation (GIF), a local NGO, to develop an environmental management plan and provide technical support for its environmental initiatives. Since that time GIF has initiated various programmes on Denis, developed the island’s ecotourism product and established various databases. The monitoring undertaken has come at a crucial time and has recorded some major landmarks in the natural recovery of the island’s ecosystem post the 2002 rat eradication.
Over the last year Frigate birds have established a regular roost on the island with up to 50 birds being recorded; and a relatively large roost (200 – 300) of Bridled terns has also started to utilise the island out of breeding season.

Ground nesting seabirds are particularly vulnerable to rats and cats and so seabird occurrence has been monitored closely. In November of 2007 there was a most encouraging discovery of a small colony of wedge-tailed shearwaters. This bird excavates burrows underground in which to roost and breed. The new colony consists of only 20 or so burrows but has expanded over the last year and represents a major breakthrough in the recovery of the island’s ecosystem.Over the last 3 years a few pairs of white-tailed tropicbird have been noted to breed on the island in some tree cavities and also one high up in the lighthouse! What was really awaited however, was the first occurrence of ground nesting. Then last month, having seen none over the preceding 3 years, 3 adults were found nesting on the ground within 24 hours and the island now has its first tropicbird chick in a ground nest!!

These discoveries are fantastic news as they really show that the island has turned a corner in its recovery such that wild species like the shearwater and tropicbird are once again finding it suitable to establish colonies.

These developments are the fruit of 10 years of work and investment by Denis Island and show that man can work to restore island ecosystems and furthermore do so within the context of tourism and landscape production activities. This progress demonstrates that development and conservation can be undertaken side-by-side and indeed in the case of Denis can be considered interdependent. After all it is the revenue from the tourism development and landscape production activities that subsidises the rehabilitation and conservation programmes. Now these programmes have in turn resulted in a healthy and more productive ecosystem and an enriched ecotourism product for the resort.

Tori’s View.

2008-10-16T23:00:00.000-07:00

I have received word from our volunteers Tori Yates and Vicki Wheeler who have graduated from their course with distinction so congratulations to them both!!! Tori has been kind enough to write a post about her time on the island which I attach below.

From May to July 2008 my colleague, Vicki wheeler, and I worked on Denis Island as Volunteers for the Green Islands Foundation. Sitting now in my flat in Reading, UK; Denis seems a million miles away! Vicki and I worked on two projects on the island:
· a project to re-establish a sooty tern colony, and
· a project to investigate the hermit crab populations on the island their status and habitat associations.
These projects contributed to our MSc studies on Wildlife Management and Conservation at the University of Reading.
We arrived on Denis at the end of May with Professor Chris Feare, a leading expert on the Sooty tern with a long working experience of the species in Seychelles, to set up the sooty tern project.
To try to lure the birds we used a mixture of 3D, 2D models and loud speakers that played the colony noise of Sooty Terns. Similar projects had been undertaken in the past in North America on Least Terns and Arctic Terns but it had never been tried with Sooty Terns before. The experimental site was set up on the south of the island in an area of cleared coconut trees as Sooty Terns nest on the ground. During the two months we were on the island a total of 24 birds landed in the experimental site and exhibited a 95.7% preference for a specific combination of models and vegetation type. These highly significant findings on preference will allow a much more targeted management of the area during the second season of the project. The impact of broadcasting colony noise was vital as 100% of circling behaviour and bird landings occurred when the speakers were playing the colony noise. At the end of the nesting season the site was rearranged into a tighter knit colony using half of the available space. 30 of the models were painted with juvenile markings and these were interspersed with the adult models. This was to make the site look appealing to overflying or “prospecting” birds looking for a nesting site for the next year. (Ed: I was supposed to follow up on this the next month but unfortunately broke my arm and was unable to undertake the work. Occasional observations by others, however, suggest that this reformulation was very successful in attracting groups of birds to the area – see posts of 13th October and 21st September). The Sooty Tern colony experiment will run in 2009 and I am very hopeful that next year more birds will come to the site and a colony will be established.

While we were on the island Vicki and I also undertook a study of the hermit crab populations, so if you visit Denis and see crabs with numbers on their shells, this is not a strange phenomenon, but rather us giving each crab we found a unique number. Little was known about the hermit crabs on the island, and while we were there we found there are three species and they all prefer the native coastal vegetation. Vicki and I had a fabulous time on the island and we were really happy to have helped the GIF and the owners of the island find out more about the wildlife they have on Denis. While we were on the island, Vicki and I worked really hard, going out and sampling crabs or monitoring the Sooty Tern site everyday but we greatly enjoyed the experience and I know that we would both like to return to the island in the next couple of years when hopefully there will be a thriving Sooty Tern colony! We would like to thank in particular Mr and Mrs Mason for their hospitality by allowing us to live and work on their island, and also John Nevill for all the assistance he gave us while we were on Denis.

Bird Bulletin 8

2008-10-15T03:49:00.000-07:00

Crested Terns. These beautiful birds are still with us and indeed I recorded my highest count for Denis yet, on Friday 10th October, with 14 birds perched on the southern rocks.

Bridled (re)Terns. Having recorded a bridled tern roost of 200 – 300 birds on the island October through December last year, I have been on the look out at the southern point of the island where the bulk aggregated last year but without success. Then on Saturday 11th I was undertaking the first beach check of the new hawksbill turtle season when I noticed all five buoys off the west of the island were being used as perches by bridled terns. This gave an inclination that birds might be returning and sure enough further down the coast in the branches of a prominent casuarina tree I counted 15 bridled terns and 10 lesser noddies. The southern point of the island however still shows no sign of bridled terns and so I will keep monitoring this small roost area to see if it expands as the weeks pass.

Frigate birds. I have still to go and check properly on our Frigate bird roost as the right time usually clashes with other commitments but on the evening of Friday 10th I saw 29 Frigates flying very low over the island towards their southwest coast roost area.

Blue pigeons. I have written at length on the blue pigeons on the island in other posts (most notably the August 10th post entitled “Natural Recolonisation 1”) and the population continues to do very well. On Saturday 11th I saw two fledglings together accompanied by an adult in a small Morinda tree. The various ornithological reference works do state that the birds will occasionally have a clutch of two eggs, though I have personally never seen this, but this sighting seems to suggest the successful fledging of a clutch of 2 on Denis.

King Myna. The Myna birds on Denis have taken to imitating the call of the Magpie robins already causing me stop more frequently to verify whether I am indeed hearing a robin or not. I have also seen on 3 or 4 occasions recently, at Belle Etoile, what is known as a “King Myna” – i.e. a Myna bird which has no feathers on its head or neck thus revealing the yellow skin all over its head to quite startling effect.

Fairy Tern and Tropicbird Progress (3).

2008-10-13T23:56:00.000-07:00

So back to our breeding seabirds for an update. Firstly the Fairy terns:
the first juvenile looks well and fully-fledged with only the lack of the purple band at the base of its bill to distinguish it now from an adult.
the second juvenile took me by surprise by flying off as I approached! It circled for a while and then returned but I kept my distance so as not to disturb it again. The bird still has clear juvenile barring on its wings and has not developed yet its full tail plumage but is clearly developing well.
Finally our egg has hatched and we have new young chick on the branch I have opted to name this bird “Fred” and will keep you informed of his/her development.

As for the tropicbirds:
· It does appear that the first nesting site has been abandoned.
· The adult is still at the second site and appears to be incubating.
· Our chick, to be known hence forth as “Tina”, has attracted a great deal of attention and feedback following my posting of its picture on the blog. Tina appears to be doing well with evident of growth over the last week.
Because of the relatively low number of breeding pairs of Tropicbirds on Denis I have decided to map the known breeding sites and will seek feedback from island staff to make it as comprehensive as possible before posting at a future date.

Sooty Tern Summary 2008 (Part 2).

2008-10-13T04:08:00.000-07:00

This post follows on from my post of 21st September.

Once the area had been selected the next issue was to identify an appropriate form and source of models. As part of the scientific basis of the project we wanted to offer the birds a variety of stimuli in various combinations so as to properly assess their preferences. We investigated various options and ultimately went for 3 types:
· Moulds were made in the UK to enable the production of fibreglass models in Seychelles.
· 2-dimensional models were made out of plywood and painted
· Plastic models of crows were bought in UK and repainted and tails added to resemble sooty terns.
Unfortunately for some technical reason, that frankly still escapes me, the moulds and particularly their rubber interiors were not suitable for the local production of fibreglass models. So we were left with two types.
The sound system used to broadcast colony noise was purchased from a company that makes sound systems to scare pest species off crops in Europe. This was modified to play the noise of a sooty tern colony.
These different options plus control plots were combined with variations in vegetation management to generate 8 different stimuli combinations each repeated twice over the project area.

Vicki Wheeler and Tori Yates arrived at the end of May and set out the project with Chris Feare and the help of the Island Manager Camille Hoareau.

Observations were taken at set times (day and night) from a viewing platform constructed at one side of the project area. The interaction of Sooties with the trial area was recorded in terms of time spent overflying the area, height of flight and of course landings within the area. Tori and Vicki were equipped with night vision glasses to assist their nocturnal data collection.

Without going into specifics (because there are papers to be written and much more work to follow over the next 2 to 3 seasons), the area was successful in engendering interest amongst overflying sooty terns including numerous landings and demonstrating a clear preference for certain parameters.

At the end of the season models were re-positioned to reflect the favoured formulation and some 30 were re-painted as juveniles to give the impression of a successful small colony. I was supposed to follow up on this closely for another month but unfortunately broke my arm at that time and didn’t visit the island for a period of 5 weeks. However, occasional sightings by at least three individuals confirmed that the new formulation was particularly successful with 5 -10 birds seen to land at a time and numerous birds circling low overhead.

So with the results of the first season now gathered, it is for us to refine our approach accordingly for next season and hopefully optimise the scope for the establishment of a small breeding colony. It was certainly a most encouraging first year!

Bird Bulletin 7

2008-10-07T05:20:00.000-07:00

Sunbird sighting: following on from my post of 15th September (in BB 6) Catherina has again sighted the male sunbird in the same location (to the north of the island) on both the 2nd and 3rd of October. Now we want to know from which of our nearest neighbours, Bird or Aride islands, the bird has originated. Catherina has also been able to get a reasonable view of the rings and I have communicated the combination to ICS, the agency that manage Aride island to see if it is one of theirs. I must also contact Nature Seychelles to see if the bird is one of those they introduced to Bird Island a couple of years ago. I will keep you informed and if the bird is indeed from Aride it will be an interesting addition to our knowledge of the species and its status on Denis (see my post dated of August 23rd for more information).

Seychelles Magpie Robin Update: love is blossoming on Denis! Well at least amongst the Magpie Robins with two more pairs appearing to establish. Most notable is the movement south of the single female from the area adjacent to territory 3 down to join the lone male there to form a new pair (see maps in side bar). Also the younger female that was co-habiting in with two other birds just south of the runway has apparently left this area, leaving anew pair behind her, and commenced floating. It is to be hoped that she will next turn up with one of the males on the northeast coast. This would result in the current optimum number of 9 pairings and hopefully engender more breeding activity. News from other territories includes:

T1 appears to be nest building again following the earlier loss of its chick.

T3 are feeding their fledgling.

T4 is currently incubating with hatching presumed imminent

T5 is nest building after an apparent failure at egg stage of a previous breeding attempt.

Following a request for a larger map I have posted the map showing territory changes here in the body of the text. Simply click on the map to see it as a full screen version.

Crested Terns: Are still with us with eleven seen together on the southern rocks on October 3rd.

Purple Heron: I have been in contact with Mr Adrian Skerrett in his capacity as chairman of the Seychelles Bird Record Committee (see link in sidebar) and he confirms that Catherina’s sighting, recorded in my post below, is the first substantiated record of the species on Denis. Catherina will submit a completed record form and photo to the committee for their final confirmation in order to make the record official.

Migratory Birds Report 1

2008-10-05T22:53:00.000-07:00

As promised, as the northern hemisphere winter draws in, Catherina and I have been monitoring the occurrence of migratory birds on Denis so as to begin to establish a proper baseline of occurrence. The northern location of Denis within the Seychelles archipelago makes it an important landfall for migrating birds to either rest up en route or to stay and overwinter.

Turnstones (Arenaria interpres) and Whimbrels (Numenius phaeopus) are present all year round but numbers have increased noticeably in recent weeks. The turnstones occur in small flocks all round and on the island so overall numbers are very hard to assess. The Whimbrels however tend to aggregate particularly on the reef flats that fringe the island’s east coast and number currently between 80-90 birds.

A common sandpiper (Actitus hypoleucos) is to be seen on the east coast since September 17th and individuals of both lesser and greater Sand Plover (Charadrius mongolus & C. leschenaultii) have been seen during September. There are 3 or 4 Grey plovers (Pluvialis squatarola) on the island and its keening call is commonly heard at Belle Etoile.

On October 3rd however, Catherina saw and photographed a beautiful Purple heron (Ardea purpurea) at Belle Etoile possibly the first confirmed record (I will check on this) for this species on Denis.

Fairy Tern and Tropicbird Progress 2.

2008-10-04T00:58:00.000-07:00

The first thing I did on arrival on Denis this week was to go and check on the fairy terns we have been following and it was good news all round.

The first juvenile shows good development since my last report with tail feathers now fully developed “she” must be approaching full fledging.
The second juvenile has grown dramatically! Gone is the fluffy ball of a chick from the last report and the development of proper plumage is now apparent.
Meanwhile the fairy tern egg remains safe and sound on its branch under the attentive incubation of its parent.

Later that day I went in search of the three ground nesting tropicbirds that I first reported as a new occurrence on Denis on Sunday the 14th of September (Post entitled “Another landmark in the restoration of Denis Island”) and here also we have progress:

The first nest area was vacant and no egg, or evidence of an egg, was apparent so the status of this “nest” is not clear. The depression left by the adult was still visible as was the presence of droppings; so the adult may have yet to lay its egg or it may be that it has abandoned the site.
The adult was still present in the second location and I assume that it is incubating though I have yet to see an egg.
However on going to the third site at the southern point of the island I was delighted to find a beautiful tropicbird chick. The chicks are absolutely stunning (see photo in sidebar) when young and hopefully as a ground-nesting population establishes will provide a great addition to the island’s ecotourism product. More importantly however this is the first confirmed tropicbird chick to hatch on the ground following the eradication of rats in 2002, this marks another landmark in the rehabilitation of the Denis Island ecosystem.

Managing for the future. The hot dry spell we have been experiencing on Denis recently reminded me that on other islands where I have worked in the past measures are taken to enhance locations for tropicbirds to nest. These measures focus on limiting the amount of exposure to direct sunlight by appropriate placement of palm leaves and providing greater security to the site by ringing it with stones. The latter measure in addition to providing the adult with a greater sense of safety and concealment may also serve to protect freshly hatched chicks from crab predation when adults leave to gather the chick’s first meal. It may be that the first site, if it turns out to have been abandoned, has been exposed to too much direct sunlight for the adult to cope with. So I will broach the topic with the island management in the coming days to see whether we can manage some potential nest sites in the vicinity of those already established in attempt to attract more adults into nest.

Nature Watch (2)

2008-10-03T22:56:00.000-07:00

Dry weather: Flying in to Denis Thursday morning (2nd October) the colour of the vegetation immediately drew my attention. We have been experiencing a dry spell in the central archipelago for a few weeks and of course this is always more pronounced on the low-lying islands which by the nature of the their topography attract less precipitation. The island presents a much less verdant spectacle from the air than usual with the greens somewhat faded and many of the grassed areas showing brown. The exception to this is the foliage of the Indian almond trees in the forest which appear to be sporting a fresh growth of leaves.

Obviously dry weather has implications for the island’s entire ecosystem, in particular it typically results in a consequent reduction in insect populations. The Seychelles warbler and magpie robin are both insectivorous birds and dry weather will result in a reduction of their food source. For the warblers this will typically mean a cessation of breeding activities until the next decent period of rainfall. For the magpie robins they will rely further upon the thrice-daily stocking of their feed stations by Catherina. It is for this very reason that Catherina’s work is so important. The foundling population of robins on the island require support to maintain them in good breeding condition. It is essential for the future prospects of the population that it get off to a good start with breeding success such that numbers can increase and make the population more resilient to natural perturbations in the future. In addition to this we are taking other measures to enhance their feeding habitat and I will cover that in the next posting of the SMR news in the coming days.

That afternoon I undertook my usual walk around the island to follow up on various issues. On reaching the grassland area called “Belle Etoile” on the island’s east coast I was struck by how the grass had died back revealing features and contours of the terrain that are normally smothered by thick herbaceous growth.

I checked on the small colony of wedge-tailed shearwater burrows, that I first mentioned in my post of 18th August “Re-colonisation 2”, and was pleased to note several new burrows further down the coast. This is very encouraging and I will keep monitoring the colony in the hope of establishing proof of breeding in the coming months.

I then continued south to check on the status of the ground-nesting tropicbirds - I will post on their status and that of the fairy tern chicks we have been following in the coming days.

As I write this we are experiencing a sudden cloudburst which will certainly help to revive the vegetation and I understand from the national meteorological office that they are forecasting a normal transition into the rainy season in the coming weeks. It can’t come too soon for Denis.

Humpback whales: on the 7th of September I posted on the sighting of 3 humpback whales offshore. On the 25th and 26th September hotel guests were treated by a much closer visitation by a mother and calf which spent the best part of 2 days within a few hundred metres of the Northwest coast of the island with the mother adding to the spectacle by occasionally breaching.

I have now (11:00 hrs Friday 3rd October) just been advised that whales are again visible today off the island’s southwest coast. See my post of August 20th entitled “Marine Megafauna” for information on the fantastic wildlife to be seen in the waters around Denis.

SMR News 4: Three steps forward two steps back…

2008-09-29T00:25:00.000-07:00

Firstly let me apologise for the delay since my last post. I usually try and post on average every 3 days or so, but bureaucracy has caught up with me of late with the GIF AGM last week entailing considerable preparation and ongoing follow-up.

The recovery of the Seychelles magpie robin population from a low of 12 in the 1960s has not always been a smooth one and problems and fluctuations are to be expected in a newly established population.

That is why we have been so excited by the excellent progress of the birds introduced to Denis. Of the initial 20 birds introduced only one was lost during the captive management stage following the very stressful process of the actual transfer, taking the island’s population to 19.

The birds rapid establishment of territories and subsequent pairing, however, gave the impression that breeding would very soon commence and see the population moving in the right direction.

This was indeed the case the first egg was found on August 4th and hatched on the 23rd of that month and developed well. At the same time 2 other territories established nests and commenced incubating their own eggs.

Sadly Catherina found the first chick dead on the ground below its nest in the first week of this month. It is not clear what happened:

Perhaps the bird simply fell out of its nest as sometimes occurs but it seemed too young for that to yet be the case.
More likely is that the bird was attacked and subsequently dropped by a Myna bird that was attempting to predate it. (see post of Monday 4th August for more information on the risk posed by Myna birds)
However on close inspection of the chick two “prick” marks reminiscent of the bite of a centipede were found on the chick. Centipedes are abundant in the forest on Denis – what is not clear however is whether the bird was bitten in its nest hence causing it to fall out or was it bitten when already on the ground.

The bird has been sent for post mortem but it is more than likely that we will never know for sure what the cause was.

Anyway as you can see I have known about this for some time (and hinted about the bad news in my post of Monday 15th September); however I waited as, with the two other eggs having hatched, I wanted to give some good news with the bad.

The two other chicks developed well such that on the 14th of September they were both weighed, ringed and blood sampled in line with normal procedure for birds due to fledge. The chicks both appeared healthy and weighed 55 and 50 grams respectively.

I am therefore delighted to advise that one of our chicks fledged on Wednesday the 24th September and equally disappointed to have to tell you that sadly the second was lost. Catherina found the bird on the ground near its nest and whilst it could flap reasonably well it did not appear able to stand. This bird was not expected to have fledged for a few more days and so Catherina returned it to its nest thinking that it may have inadvertently fallen out whilst exercising its developing wings. Unfortunately the next morning the chick was again found on the ground in a much weakened state and still unable to stand - it died later that day. This body has also been sent for post mortem.

I must stress that in overall terms this is still good progress in terms of numbers so soon after the introduction as one can expect several mortalities post transfer and we suffered only one. It is nevertheless of considerable concern that we should lose 2 of the first three chicks. Mortality of chicks pre-independence can be quite high and it is for this reason that we typically don’t count a bird as part of the population until it reaches full adult independence. These losses, however, do raise concerns and we are already looking at means to reduce the Myna bird population earlier than we had previously planned.

In the meantime we have a further two territories showing signs of nesting so the work and hope continues. Check back regularly for updates on the status of our fledgling and the overall population.

Sooty Tern Summary 2008 (Part 1).

2008-09-21T20:54:00.000-07:00

The sound system has been dismantled and half of the models packed away. The remaining models, having been left out as a feature for the guest’s nature walk, will soon now also be removed as video footage of the project has been added to the evening presentations.

As this first season of the 4-year programme has now closed it is appropriate to summarise the build up to and background of the project.

I first became interested in Sooty Terns (Onychoprion fuscata) whilst working on Cousine Island (1993-96). The abundance of the birds displaying and swooping low over the island, led me to believe that they must be nesting in a small colony somewhere or on the verge of forming a colony. Thorough checks during the seasons of 94 and 95 showed however that there was no colony on the island[1].

I subsequently met Professor Chris Feare, the leading expert on the species, whilst working for the Division of Environment in 1997 and we discussed the possibilities of attempting a re-establishment of a colony on island using models and colony noise playback – something that Chris had been hoping to try for some time. The issue was finding a suitable island - i.e. one that had formerly hosted Sooties, which was alien predator free and manageable in terms of resident human resource capacity and ability to prevent poaching of a newly-established colony.

Hence when GIF started to work with Denis Island in 2006 I proposed the project as part of the island’s broader ecosystem rehabilitation project. The owners were interested in the idea so I developed a concept paper in January 2007 with project outline, budget and a short list of 3 potential locations on the island. The owners approved the project and so I commenced liaison with Chris on how we could proceed.

Chris visited Denis in June 2007 and based on his advice, coupled with the islands existing Land Use Plan (LUP) criteria, we selected an area on the south west coast (see map) for the pilot project. The factors effecting the site selection included: optimal distance from the runway and hotel, a location on the west coast which suited the birds’ typical displaying activity on the nearest colony on Bird Island, compatibility with the restoration zone of the LUP and the availability of suitable flight path. Sooty terns are very graceful and efficient long distance fliers but prefer to have reasonable flight paths into their landing area. The island’s new LUP does not allow for vegetation within 25 metres of the high water mark to be removed. The final area was chosen because there is an old abandoned building on the coast there, the garden of, which provided an existing flight path through the coastal vegetation.

It is known from other colonies that Sooties prefer to nest in open ground with flat herbaceous vegetation. The area chosen consisted of a densely vegetated abandoned coconut plantation and so the next stage was to clear the area and make it suitable. Denis has an existing approval from Government to fell up to 50 coconut trees a week in order to harvest the heart of palm for the local hotel market and so it was decided to use this quota in a focused manner in the area in question. The area cleared is a little less than 2 hectares and constitutes approximately 1.5% of the island’s surface area.

It was initially intended to undertake the work from August 2007 onwards but labour shortages meant that work only commenced in January 2008. The area was cleared by the end of April which whilst it meant it was ready in time for the season also meant the opportunity to mange the ground vegetation in the desired manner through the rainy season was lost.

During this period other technical issues were also addressed in terms of the purchase of the necessary equipment and the identification of a project partner and volunteers from Reading University in the UK.

This project to re-establish a sooty tern colony on Denis Island represents a world first and as such it was determined from the offset to undertake it to strict scientific criteria. I will cover the technical preparation and implementation phases of the project in a subsequent post. So check back regularly for that and other updates!

[1] A small colony of Sooties did naturally re-establish itself on the island in 2003.

Fairy Tern and Tropicbird Progress 1.

2008-09-18T00:29:00.000-07:00

As promised, I went back to check on the fairy tern juvenile that I had “rescued” and the second chick that I found and posted on previously (see post dated September 7th “Fairy Terns Progress”) during my last visit (11-13 Sept).

The juvenile was on its branch but gave rise to some concern as it does not seem to have progressed in the intervening week and was looking perhaps a little subdued. I was later reassured to note however that it does appear to have two adult birds in attendance.

The chick was looking good showing considerable growth over the last week and again displayed its crouching/hiding behaviour when I approached.

I subsequently found a new egg on a nearby tree and so will follow this also - hopefully through all the stages of its development to a successful fledging. The Fairy tern is an interesting species that makes no nest but rather lays its single egg directly onto a branch in a hollow or cleft and incubation takes about 3 weeks.

As recorded in my second post of Sunday 14th September, I recently found 3 separate instances of ground nesting White-tailed tropicbirds. This is a very exciting development in the recovery of the island following the eradication of rats in 2002. Tropicbirds incubate for approximately 6 weeks and fledge typically 10-12 weeks after hatching.
I assume that the three birds were incubating eggs and will now monitor these nests regularly and report back in the same vein and together with my reports on the fairy tern breeding attempts in a periodic post.

Check back regularly for updates on their progress and photographs of the chicks as they develop!

Bird Bulletin 6

2008-09-15T22:52:00.000-07:00

Sunbird sighting: in my post of August 23rd I wrote about the uncertain status of the sunbird (Nectarinia dussumieri) on Denis and the limited records we have on the occurrence of the bird on the island - well Catherina has been able to add to these records. On August 19th Catherina heard and later saw a single male bird singing in a Tortoise tree (Morinda citrifolia) near the hotel laundry. Interestingly, unlike the bird spotted by Professor Feare and myself in June 2007, this bird was ringed suggesting it likely well came from our neighbour Bird Island which had a population of sunbirds introduced a couple of years ago. Catherina was not able to ascertain the colour of the rings, however, before the bird flew south in the direction of the tennis court. I do not know if sunbirds on Aride Island, our second nearest neighbour 56km to the south, are ringed but will follow up on this. In the meantime I have updated our sunbird sighting map – see sidebar.
Warbler chicks: during my rounds of the island I have noticed recently quite a few begging warbler (Acrocephalus sechellensis) chicks, as can be expected at this time of year. A couple in particular are well positioned (at the tortoise park and southern point) to provide a welcome and reliable addition to the guest nature walks. We were unable to have a survey of the warbler population this year due to the other initiatives being undertaken but I hope very much that we can have a through population assessment in 2009. I will post in the future on the story of the Seychelles warbler and its introduction to Denis.
Seychelles Magpie Robin Update: talking of tourist attractions, magpie robins (Copsychus sechellarum) are now a common sight along the islands paths and provide a thrilling glimpse of such a rare bird to hotel guests on the nature walk. I have both good and bad news regarding the Seychelles magpie robin population on the island – so keep checking back for the 4th edition of SMR news which I will post in the coming days.
Crested Terns (Thalasseus bergii): are again a frequent sight around the island. They can most commonly be seen in the mornings at Pte Madame Guichard – the sand spit just west of the main hotel complex - and in the afternoons they appear to favour the sandstone rocks of the southern point. There are approximately 8 -10 birds currently resident on the island.
Migrant Bird watch: I will be adding a new feature to the blog in the coming weeks. Aside from flocks of Turnstone (Arenaria interpres) and Whimbrel (Numenius phaeopus) which are present year round on the island we have recently been joined by a Greater Sandplover (Charadrius leschenaultii). We also had a single Crab plover (Dromas ardeola) in July but I haven't seen it since. As the northern winter draws in, Denis can expect a large influx of migratory birds and with Catherina now full time on the island we should be able to properly monitor the birds visiting the island and begin to develop an authoritative list of our annual visitors.

Denis Conservation efforts make national media.

2008-09-14T21:50:00.000-07:00

The national newspaper the "Nation" this morning (Monday 15th September) includes an article on the success to date of the Magpie robin introduction to Denis. The article includes reference to this blog so hopefully that will broaden interest in and raise awareness of our ongoing efforts. Simply click on the image below to read the full article.

Another landmark in the restoration of Denis Island.

2008-09-14T09:52:00.000-07:00

Ground nesting birds are of course the first to fall victim to alien predators such as cats and rats. In my post of August 18th I wrote about the re-colonisation of Denis by the wedge-tailed shearwater and its significance in terms of the rehabilitation of the island ecosystem post rat-eradication 2002. I am now delighted to be able to report another equivalent breakthrough and one that has real ramifications for the island’s ecotourism product.

The White-tailed Tropicbird (Phaethon lepturus) does breed on Denis but in very low numbers, maybe as few as 5 pairs in 2007, and I have been aware of only two nesting sites – one in a coconut tree and one in the lighthouse! Over the last 3 years I have been on the lookout for birds nesting on the ground as they typically do in other colonies but with no success. I have received one report from island workers of a tropicbird on the ground deep in the island’s interior (not the most likely location) and I had been unable to confirm this.

Imagine my delight therefore to find not one but two Tropicbirds nesting on the ground within 40 metres of each other on the east coast on Friday morning! It was a thrill to see these stunning birds nestled in amongst the buttresses at the base of Casuarina trees and marks another real landmark in the restoration of Denis.

To top this on Saturday morning I found a third bird nesting on the ground, again at the base of a Casuarina tree, at the southern point of the island. Having seen none over the last three years it is remarkable that I should find three in 2 days and one hopes that this marks a real turning point in the population of this species on the island.

I will monitor these sites closely over the coming weeks to see how these breeding attempts progress and report developments on the blog along with those of the fairy tern chicks I am following (see post of September 7th: “Fairy Tern progress”) – so keep checking back regularly!

News Summary

2008-09-14T09:39:00.000-07:00

Just back from Denis and have plenty to report on including:

the latest landmark in the ecosystem restoration of Denis.
an update on the progress of the fairy tern chicks I have been reporting on over the last two weeks.
the first report on the impending migratory bird season.
news on a new sunbird sighting,
the end of the first season of the sooty tern project, and of course
the latest magpie robin news round up.

I will endeavour to cover all these points over the coming week or so but preparations for the Green Islands Foundation Annual General Meeting, amongst other things, may mean posts are somewhat abbreviated.

Nevertheless check back regularly to catch these postings and to keep abreast of the latest environmental news from Denis Island.

The Importance of Crabs!!! (Part 2)

2008-09-10T04:03:00.000-07:00

I have received a summary of findings on the Hermit Crab survey (see post of July 16th) from our volunteers Tori and Vicki. The hermit crab plays a very important role in Denis Island’s ecosystem and it had been anticipated that we would see a population explosion following the eradication of rats in 2002. This, however, has not materialised and so further research was required in order to understand the population dynamics of the three species we have on Denis - the Tawny hermit crab (Coenobita rugosus), Red hermit crab (C. perlatus) and the Purple hermit crab (C. brevimanus). It is also important for us to have a better understanding of the habitat preferences of the species before we embark on the more extensive vegetation management foreseen under the islands Environmental Management Plan.
Vicki and Tori used quadrat surveys and pitfall traps to monitor the occurrence of hermit crabs in different vegetation types and “capture-recapture” techniques to derive an understanding of the crabs’ population densities.

Crabs were found to be more abundant on the east and southern coasts (beaches and supralittoral zones) and showed a correlation with areas of coastal vegetation dominated by Veloutye (S. sericea) and Beach Gardenia (G. speciosa) – see post of 27th August.

Though active throughout the day hermit crabs are found in greater numbers in the evening and night time. On Denis the purple hermit crab is the least common and is seldom found on the beach preferring more inland habitats such as the supralittoral zones and interior pathways. The tawny and red species were found in diverse habitats with the tawny hermit crab being the most abundant.

In addition to vegetation the research identified what may be the key factor behind the relative lack of large hermit crabs on the island. Larger hermit crabs are typically found in shells of the Turbo genus, while smaller crabs (defined as those with large chela/pincer less than 10mm) mainly utilise the shells of the mollusc Nerita plicata. The beaches on the southern and east coasts are surrounded by reef flats that support large numbers of Nerita and in these locations large populations of small hermit crabs were found. Larger crabs were however comparatively scarce and many of them were found to be in shells that were unsuitable i.e. cone shells or Turbo shells that were far too small –such that all their limbs remained exposed when they attempted to retreat within their shells. This suggests that there is a lack of suitable, larger shells available on the coasts of the island.

GIF focuses on research that has practical management applications; so what are the ramifications of these findings?. The improved understanding of hermit crab habitat preference will enable us to incorporate their needs into vegetation management ensuring the right conditions prevail for this important component of the ecosystem.
The issue of shell availability will be approached in 2 ways:
• Firstly a large portion of the southern beaches are to be managed as “no-take zones” where notice boards will be put up requesting guests and workers not to collect shells from the beach in the hope that shell numbers on the beach will gradually increase with time.
• Secondly, many old semi-fossilised turbo shells can be found inland in the soil and the gardening team have been asked to collect all the old shells they encounter. Once a good number have been collected – say 50 – 100 – they will be cleaned, measured and numbered before being put out in 1 or 2 specific coastal locations. Ongoing monitoring of the population will then show whether the average size of crabs in these areas increases relative to elsewhere around the island and thereby determine whether shells are indeed a limiting factor in the recovery of hermit crab populations on Denis.

Sounds like more work for future volunteers!