SMR News 4: Three steps forward two steps back…

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).

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.

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

• 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.

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.

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

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)

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!

Nature Watch.

Playful whales: Coming in to land on Denis, I always pay close attention to the shoal around the island. The Air Seychelles STOL Twin Otter always does a flyover to allow the pilots to check that all is in order on the runway before the plane circles and comes into land. This means the plane banks slowly over the shoal at relatively low altitude before making its final approach. When the sea is clear you can make out a great deal of detail in the waters below. I have in the past seen pods of dolphins, manta rays, hawksbill turtles and once a large shark that I took by its shape and slow progress to be a grey nurse shark. Taking off generally doesn’t give as much time to see anything with the plane’s rapid ascent and direct route to Mahe. Take off on Sunday the 31st of August, however, provided me with a new experience. The plane had just departed Denis flying eastwards and was still gaining height when my eye was drawn to a large splash on the surface about 2000m offshore of the island.
It was immediately apparent by the size of the three animals, I could see silhouetted in the water, that they were whales. As I watched the animal in the middle broke the surface again in a “porpoising” action revealing a pale underside with characteristic grooving in the skin running from mouth down the “throat” towards the belly. A few seconds later the whale repeated the action again revealing the same features and was this time also seen by the passenger seated behind me.
The features described are characteristic of humpback whales which are known to occur in the waters around the Seychelles plateau and this may have been a playful sub-adult enjoying itself amidst a family group. The three animals were soon lost behind us as we angled off to Mahe, but nevertheless was another insight into the natural wonders that can be encountered around Denis.

Fairy Tern progress: I have posted previously on close encounters with birds (see post of August 13th) and also on the island’s tern populations (see post of August 24th) noting in particular that there had been a high rate of mortality amongst fairy tern chicks. The two issues converged last week when whilst doing my normal photo survey of the beach profile adjacent to the main hotel complex I encountered a juvenile fairy tern perched amongst some twigs on the beach crest. It had clearly fallen from its proper perch and under other circumstances I would have left it undisturbed as the adults will continue to feed such birds. But its location is so heavily frequented by people that I felt it best, with the aid of a beach chair, to find a suitable prominent perch for it on the nearest Casuarina tree. I have in the past on other islands moved many such juveniles when for example a tree falls in a storm or has to be cut for safety reasons and, provided a suitable adjacent perch can be found, the parents will typically soon find their offspring and continue to care for it.
Fairy terns are said to take 50-60 days to fledge[1], though I know from my own casual observations over the years that development can be delayed significantly in times of food shortage. This juvenile had quite well developed plumage but still exhibited tufts of its fluffy chick’s plumage. Having done this I headed north along the coast and soon encountered an adult fairy tern with its relatively newly hatched chick in a Cordia tree and took the opportunity to photograph this most photogenic of scenes.
On my return this weekend I went to check on these juveniles. The rescued bird had migrated up from its perch to an adjacent branch and appeared to be in good health with nearly all evidence of its juvenile plumage now gone. Pleased with this I moved further on to check on the young chick which was sitting proud on its branch. Interestingly as I approached instinct caused it to crouch down on the branch such that it would have been largely invisible had I not already known its location. The chick had clearly grown over the preceding week and looked well.
I will check back on these birds regularly and let you know how they progress – let’s hope that they break the recent trend and both progress successfully through to fledging.
[1] Skerrett et al 2001 referring to an Aride Island report by Bullock.

One thousand hits and counting…

Thank you very much to all readers of this blog…

During the night of Monday 1st September the hits counter clocked up 1000! I added the counter on the 5th of August which equates to an average of 35 hits a day – a very encouraging beginning!

I have received feedback from such far flung parts as Australia, Jamaica, New Zealand, Taiwan, UK and the US - this “inter-web thingy” really is amazing!

The challenge now of course is to try and maintain and or even improve on this readership and increase “market penetration”. I have a few ideas in this regard:

• I hope to create linkages with other environment and tourism related sites and I am currently in discussions to that end.
• I hope to make occasional contributions to the National newspaper here in Seychelles and reference the Blog accordingly.
• Also I hope to get more contributions from others involved in the work on Denis so that readers can benefit from different perspectives.

I would also welcome more interaction from readers. Please feel free to ask questions or seek further information on postings by using the comments option.

To facilitate your access to the blog:

• Keep informed of new updates by utilising the subscription tool at the foot of the page.
• Add the site to your favourites list,
• or even make it your browser homepage!!!

Please do keep checking back periodically for updates as we certainly face a very interesting time on Denis in the months ahead!

Thanks again for your interest… JN.

Seychelles Magpie Robin News 3: Denis Island breathes new life into the Conservation of the Seychelles Magpie Robin.

The first, of hopefully many, Magpie Robin chicks has hatched on Denis Island whilst two other eggs are under incubation!!! This is the great news coming from Catherina on Denis. I went to Denis over the weekend and caught up on the news and developments. In addition there are another two pairs of birds that are currently nest building and a further two birds that are showing signs of forming a breeding pair. This is all very encouraging news and is the culmination of years of work on the part of many partners.

For many years (1960s to mid-1990s) the Seychelles Magpie Robin (SMR) was confined to Fregate Island with a precariously low population – once estimated to be as few as 12!!! In 1981 well-known local conservationist, Victorin Laboudallon, was part of the team, along with a consultant from the New Zealand wildlife service that went to Fregate to eradicate cats on the island that were then threatening this last population of SMRs.
In the late 1980s Dr Jan Komdeur, working at that time for the International Council for Bird Preservation (now called BirdLife International) began work on understanding the ecological needs of the robins on Fregate and investigating scope for supplementary feeding to improve their breeding success etc…

In the following years a recovery programme was initiated by BirdLife International and birds were transferred to and populations established on the small islands of Cousin and Cousine in the mid-1990s. In 1998 the management of the recovery plan was localised and taken over by Nature Seychelles (called at that time BirdLife Seychelles). A population was also established and after some initial difficulties subsequently stabilised on Aride Island. These islands however offered relatively small areas of habitat and even with ongoing vegetation rehabilitation, particularly on Fregate, the scope for ongoing population growth was limited.

The next phase in the SMR conservation story came with a programme of rat and cat eradications on private islands. Fregate Island had unfortunately been invaded by rats in 1998 and they were successfully eradicated in 2000, Denis Island eradicated cats in 2000 and rats in 2002. The removal of alien predators from Denis coupled with a habitat rehabilitation programme in partnership with Nature Seychelles made Denis the next priority island for the introduction of the SMR.

On the 25th June this year, 20 SMRs (16 from Fregate and 4 from Cousin) were transferred to Denis (see post dated 04/07/08). The birds were released from their aviaries in a staggered process from the 13th to the 18th July (see post dated 20/07/08). Several birds soon paired off, established territories and commenced nest building (see posts dated: 30/07, 04/08 & 15/08/08). Catherina noted the first egg in territory T2 (see map 4) on the 4th of August and it is believed to have hatched on the 23rd. She noted an egg in the nest of territory T1 on the 16th (likely laid a day or 2 before that). Finally she observed an egg in the nest in T3 on the 16th with egg having been laid in the preceding 2 or 3 days. Preparations are also underway in territories T4 and T5 with nests under construction and the pair in T5 observed mating twice.

For Denis Island and its owners this is the latest landmark on a restoration process they commenced in 1998 with the initial alien predator surveys. A lot of resources have been and continue to be invested in this undertaking to the benefit of the Seychelles Magpie Robin and conservation in Seychelles in general. Populations of Seychelles Warbler and Fody, introduced in 2004, and are doing well on the island whilst sea bird colonies are also showing signs of recovery (see posts dated: 18/08 & 24/08/08).

Of course the first chick still has a long way to go before it is considered an independent adult and faces various risks along that path – but its hatching and the progress in four other territories really is a fantastic start for the Denis introduction and literally breathes new life into the conservation of the Seychelles Magpie Robin a species still classified as endangered under World Conservation Union (IUCN) criteria..

Check back regularly for updates on the population’s progress.