Saving Paradise

Bulwer's Petrel Cousin Island, 15 June 2009 Photo: Martyn Hammers

In July 2009 we brought you the news of the sighting of what was presumed were Herald’s and Jounin’s Petrels on Cousin Island – See this post.

Well it turns out that the Jounin was actually a Bulwer’s!. The Seychelles Bird Committee has come back with a confirmation of this sighting as a Bulwer’s. You can read more about this authentication (and more Petrels on cousin!) on our website

This is me holding a Lesser noddy

Hello. My name is Ian Valmont. Am the new Island Coordinator for Cousin Island. I wanted to introduce myself and also to let you know that I will be a regular contributor to the Blog.

A little about myself. Am not a stranger to Cousin Island. For the past decade, I have worked mainly for Nature Seychelles and spent a considerable amount of that time on the Island.

Iam a keen birder and I enjoy being on Cousin which frankly is a birder’s paradise. Very few people are this lucky. There is always something interesting going on. I have just been taking pictures of a Northern Pintail (Anas acuta) that’s been wintering here since December. It’s on its own. For those who might not know the Northern Pintail is a duck that breeds throughout North America and northern Asia, but comes to our parts as well as Africa, India, Burma, and Japan for the winter. The vagrant ducks are found in the granitic Seychelles from November to December. In the north it would be found in shallow, wide open tools and lakes. But it uses coastal waters during winter. This one sure knows how to pick its vacation spot!

This Northern pintail has been vacationing on Cousin since December. A word of advice mate, next time bring someone!

On the Island I will be coordinating conservation and research on some of Seychelles rarest bird species, including the Seychelles warbler (Timerl Dezil in Creole), the Seychelles magpie-robin (Creole: Pi Santez) and the Seychelles fody (Creole: Tok Tok). I am a bird ringer with accreditation from South African Ring (SAFring), specializing in the endemic passerines and seabirds. I have rung and taken biometric measurements of more than 500 individual birds. This experience has  provided me with the opportunity to visit some of Seychelles unique places with important bird populations such as the Aldabra atoll in the southern part of the archipelago. I have also helped to rehabilitate habitats on other islands in the Seychelles for the re-introduction of endemic bird species.

I take an interest in all aspects of nature. For the past year, I have been involved in monitoring of roosts for the endangered Seychelles Sheath tailed bat on Mahe. I have a passion for mentoring younger Seychellois in conservation. So am looking forward to moulding younger and newer staff to be the best, ensuring that Cousin is one of the best-run Nature Reserves in the world

I look forward to conversing with you our readers. I would be happy to answer any questions you have about Cousin.

Ian.

Italian visitors to Cousin Island Special Reserve now have access to information on the Island in their own language thanks to Prof. Massimo Pandolfi of the University of Urbino and the Seychelles Heritage Conservation Study Group. Prof. Pandolfi recently presented Nature Seychelles with an Italian version of the Cousin Island tourist information leaflet he helped produce with his colleagues. Pandolfi was responding to a need for a third translation of the leaflet that is currently in English and French.

See video below of the presentation of the guide at our offices in Roche Caiman.

Vincent Nedderneijer is a 26 year old MA student from the University of Gronigen in the Netherlands. He has come to the Seychelles to join the study group that carries out research on Seychelles warblers. The study has been ongoing for a decade now, and brings together the University of East Anglia, University of Gronigen, University of Sheffield and Nature Seychelles and others.

The Seychelles Warbler, you may recall, was the reason that in 1968 BirdLife International (then the International Council for the Protection of Birds) purchased Cousin Island. At the time the warbler was sliding dangerously towards extinction. Cousin Island provided a home and helped save  the warblers, and also provided a home for other endemic species. There have now also been successful trans-locations of warblers from Cousin to other islands – Cousine, Aride and Dennis.

Vincent’s Master’s is on Behavioural Biology. He was thus keen to be involved in any study of animals in the tropics. He was happy to end up in the Seychelles, he says. “What I have seen looks sensational. It’s what I had expected, maybe a little more”. He has previously been to Namibia, Botswana and South Africa. On Cousin Island he will share a home with seabirds, land birds including 5 endemic species, reptiles and mingle with the wardens and other volunteers.

This blog will keep you up to date with Vincent’s experience’s.

Read about: Cooperative breeding in the Seychelles warbler in last issue of Zwazo.

Happy New Year

We have good news here. The waiting period – approximately 60 days – is over and hatching of Hawksbill turtle eggs laid on the Cousin beach has began. Mary and Eric have had a busy time with turtle work. The work continues with the hatching. As reported earlier, apart from the regular monitoring program based on beach patrols carried out around the island to intercept and collect data on as many turtles as possible, Nature Seychelles – with technical assistance from Kelonia Marine Turtle Observatory in Reunion – this season introduced the use of data loggers to measure temperature in selected nests. Temperature inside the turtle nests is known to determine the sex ratio of hatchlings. Warmer temperatures produce more females and cooler temperatures give more males. This is an important area of study, as with rising global temperatures, it is important to understand the potential impacts of climate change on this critically endangered and thermally sensitive species.

When hatching occurs in the nests with data loggers (30 in total) Mary and Eric pick up and measure the weight and length of 30 of the hatchlings, as well as categorizing nest content to determine hatchling success.

They are then put in basket such as the one below with a shadow to avoid dehydration.

When the sample hatchlings have been measured  and weighed, they are released and head out to sea. The release is controlled to avoid the high level of predation by ghost crabs.

It is impossible to tell the sex ratio of the hatchlings when they are this small. But from the data collected from the data loggers it is possible to determine the approximate sex ratio using existing and new temperature data. We will give you more information on how this pilot study evolves.

The calm seas over the last few weeks provided the perfect opportunity for coral reef monitoring to get underway on Cousin, Mary one of our volunteers reports. Three sites have been surveyed, representing the different habitats around the island. A team of 4 divers have been collecting data on the benthic, fish and invertebrate communities in addition to documenting coral recruitment. With these first surveys completed, regular monitoring will continue in the future to help us document any changes which are taking place on the reefs.

Coral reef monitoring © Conor Jameson

Cousin Island is one of the longest established marine reserves in the world and the coral reefs surrounding the island have undergone many changes over the last few years. Like other reefs in Seychelles they were particularly badly affected by coral bleaching in 1998 which led to a dramatic reduction in live coral cover and a resultant increase in algal cover. Given the importance of coral reefs as sites of high biodiversity it is important to document these changes in order that these resources can be effectively managed and preserved. This can be achieved through regular monitoring of these ecosystems to keep track of any changes which occur.

It is that time of the year again and hawksbill turtles are making their annual pilgrimage to our shores to nest. The hawksbill breeds throughout Seychelles, peaking between mid-October and mid-January.  On Cousin Island, Conservation Officer Eric Blais reported an early appearance on August 8. Appearances are starting to pick up now and more turtles will arrive in November, December and January.

As numbers peak, so will monitoring. On a short visit to Cousin yesterday (9 Nov 2009), I took part in an afternoon monitoring exercise with Eric, David (Science Coordinator for Nature Seychelles), Mary (a volunteer helping with the turtle work) and Claire (from Kelonia) to see just what this means.

Cousin Island has one of the longest running monitoring programmes – started in 1972 – forming a core part of the wardens and volunteers work programs. Appearance dates and locations have to be recorded, with nesting beaches being patrolled several times a day. Metal tags with unique identification code, attached to the front flippers of each nesting turtle encountered help identify individual females returning to the beach each season.

Turtle emergences are recorded under four categories of behaviour: 1) “LAID” during which eggs were laid after digging one or more nests; 2) “Did Not Lay (DNL)” during which one or more nests were dug but no eggs laid; 3) “Half Moon (HM)”emergences during which digging did not occur although no disturbance factors were apparent; and 4) “Emergence Stopped by Obstacle (ESBO)” during which no digging occurred because the female was discouraged by obstacles on the beach.

After a short walk, we came across a female who had just begun to dig her pit. As I took covert pictures of her, my colleagues went about taking their data and doing their tagging. To my utter surprise Mary put her hand into the pit and with a counter in the other, began to tally the eggs as they came out.

A female turtle crawls out of the sea and using her front flippers drags herself up to the beach to a suitable nest site. There, she digs a pit with her front flippers and then excavates a vertical egg chamber with her hind flippers in which she lays her eggs. Eggs can be as many as 250. Mary counted 210 eggs for this one! Afterwards, the turtle used her hind legs to cover up the nest with sand and returned to sea.

It will take close to sixty days for the eggs to hatch and two or more days for the baby turtles to get to the surface. The babies will emerge as a group and – usually at or after dusk – head towards the sea attracted by the reflection of the moon on the water. But they face a number of challenges. Once hatched, babies are a favorite food for ghost crabs, birds and fish. Baby turtles could also be affected by beach lighting, which can cause them to head inland rather than out to sea. On Cousin, lights are of low wattage and screened from all nesting beaches.

As I left Cousin, I reflected on the work ahead for these hardworking people. Things will certainly get very busy soon. But thankfully, the collection of data will be increasingly efficient due to new technology and data analysis techniques that are being introduced.

This post was contributed by Michelle Kappes and Kevin Coustaut, Laboratoire d’Ecologie Marine at the Université de la Réunion.

Shearwaters, like most seabirds, spend most of their lives at sea.  In order to learn about where shearwaters go when they are away from their breeding colonies, Dr. Matthieu Le Corre from the Université de la Réunion has begun a research program to deploy miniaturized electronic tags on wedge-tailed shearwaters (Puffinus pacificus) at sites throughout the western Indian Ocean.  These tags, or geolocators, collect data on light level that can be used to determine the position of the bird at sea.  Basically, the time of local noon is used to determine longitude, and latitude is estimated by local day length.  The tags are attached to a metal ring on the bird’s tarsus using a plastic zip-tie (see photo).  The tags also have a salt-water switch, and due to their placement, we can determine when the shearwaters are in flight and when they are resting or foraging on the sea surface.  By taking advantage of this technology, we can begin to get a picture of how these wide-ranging seabirds behave during their foraging trips to sea.

Wedge-tailed shearwater with geolocator © Michelle Kappes

Also using geolocators, recent work by Catry et al. (2009) demonstrated that 9 wedge-tailed shearwaters breeding on Aride Island remained close to the colony when raising chicks, and later dispersed up to 3,500 km to the central Indian Ocean Basin during the non-breeding period.  Last year, members of Dr. Le Corre’s research team recovered 6 geolocators from wedge-tailed shearwaters deployed at Cousin Island.  Preliminary analysis suggests that shearwaters from Cousin Island disperse further east during the non-breeding period than those from Aride Island.  However, a larger sample size will be necessary to confirm colony-specific differences in foraging behavior.

During 14-29 September 2009, we deployed 24 geolocators on wedge-tailed shearwaters breeding within St Joseph Atoll, Amirantes group, and 24 geolocators on shearwaters breeding at Cousin Island.  Field work is planned to deploy similar numbers of geolocators at sites on Réunion Island, as well as off Mauritius and Madagascar.  This will be the first attempt to simultaneously study the at-sea behavior of this seabird species across a broad range of breeding sites.

Ultimately, these data will help us answer questions such as: do wedge-tailed shearwaters breeding at different sites in the western Indian Ocean travel to similar locations at sea?  Are there specific ocean habitats that are of particular importance for this species?  Areas of the ocean that are important to shearwaters may be important for other marine species as well, so these data could be used to help identify marine Important Bird Areas and possibly oceanic Marine Protected Areas.

Shearwater in burrow on Cousin Island © Conor Jameson

However, as the geolocators store these data on-board, we won’t be able to answer these questions until we recover the tags at the end of the breeding season.  This may prove trickier than it sounds because once shearwater chicks reach about a week in age, adults only return to the colonies for brief periods to deliver meals to their chicks.  So we may have to wait until the next breeding season starts in 2010 to recover these tags and unlock the secrets of where these different populations of shearwaters spend their time at sea!

Here are some pictures taken by student Rachel Cartwright on Cousin  Island of an unusual occurrence: two Seychelles Magpie robin chicks sharing a nest. Eric Blais, Conservation Officer and  Cousin Island wardens are keeping an eye on the chicks. Cousin is home to a population of some 27 Seychelles Magpie robins. These are part of a total population of approximately 200 individuals found on five of Seychelles islands. The endemic birds were once on the brink of extinction and were classified as critically endangered on IUCN’s Red List. Their recovery through the highly successful Magpie robin Recovery Program – led by BirdLife International and then managed by Nature Seychelles  – took this species away from the brink of extinction and saw them down listed to “Endangered”.

On 10 June 2009 David Andrews – a student from the University of East Anglia/UK helping Nature Seychelles on a program on the impact of Pisonia grandis on seabirds – made a startling discovery of  a Herald Petrel Pterodroma arminjoniana on Cousin Island. In the west Indian Ocean, this bird is known to breed on Round Island, Mauritius. If the sighting and identification is confirmed by the Seychelles Bird Record Committee, it would be the first record of this dark petrel species in the Seychelles. Because it has an extremely large range, this bird is classified as Least Concern on the IUCN Red List.

The Herald Petrel, was captured, ringed and measurements taken…

To his further excitement, David also had an unusual sighting of a Jouanins Petrel Bulweria fallax on top of Cousin hill on June 15. Outside the breeding season, this pelagic and solitary bird is considered as the most frequently reported all-dark petrel in Seychelles waters, notably between Aldabra, Farquhar and Amirantes. However, it is usually recorded from October to March in the Seychelles. The sighting in June and on land is therefore very unusual. Jouanins Petrel is classified as Near Threatened by IUCN due to its suspected moderately small range, which is offshore in the Arabian Sea, and Gulfs of Aden and Oman. Its breeding grounds have recently been discovered in Socotra island, South of Yemen where approximately 50 pairs were found and  around 3,000 pairs are now estimated to nest locally on mainland cliffs.

…and so was the Jouanins Petrel.

David provided us with photos of the birds subsequent capture and ringing. The finding has been sent to Adrien Skerret of the Seychelles Bird Record Committee for species validation.