Saving Paradise

Category: Cousin Island, Turtles | Date: Nov 10 2009 | By: savingparadise

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.

Tags: Cousin Island, hawksbill turtle, monitoring

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Category: Cousin Island, Seabirds | Date: Nov 04 2009 | By: savingparadise

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!

Tags: Cousin Island, Seabirds, wedge tailed shearwater

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Category: Nature Seychelles | Date: Oct 28 2009 | By: savingparadise

This week we had the privilege of the brief company of two seabirds at our office - a wedge-tailed Shearwater, Fouke in Creole, and Wilson’s storm petrel. Both Birds had been found and rescued by members of the public.

The storm petrel before its release

The Wilson’s storm petrel was found by a fishing boat around Denis Island and was brought in to us on the afternoon of Friday 23 by Captain J P Grancourt. Upon identifying the tiny bird as Wilson’s storm petrel,  we sent out an email to the bird committee to ask for advice on its feeding and release. It had no apparent injury and seemed to be just stressed, so it was put in a box to rest. It was fed, although with some difficulty as its beak is very tiny. Petrels feed on tiny shrimps, small squids, very small fish and planktonic crustaceans. We heard back from Adrian Skerret of the Bird Committee who advised its immediate release because of the difficulties in feeding. He also said that very few records exist in Seychelles of Wilson’s storm petrel; it has only once been photographed in Seychelles. On Saturday morning the bird was released on Mahe.

The shearwater brought to our office. Inset: shearwater nesting on Cousin

The shearwater was found at Pointe Larue near the agro-processing plant. Wedge tailed shearwaters are found on rat free islands in the Seychelles such as Cousin, Cousine, and Aride where they burrow on the ground to nest. Adults leave their burrows before dawn to fly out to feeding grounds at sea  and return in the cover of darkness. They are rarely found on Mahe. The Shearwater was confused but otherwise healthy with no injuries. It is being fed and will be released in a coastal area later today.

Wedge tailed shearwaters are also known as the moaning bird because of the eerie calls they make. In the past the call was associated with ghosts. They are even said to have caused a warden on Cousin to leave the island in haste! Listen to it here and tell us what you think.

Tags: Cousin Island, Mahe, wedge tailed shearwater, wilson's storm petrel

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Category: Cousin Island, Endemic birds, birds | Date: Sep 18 2009 | By: savingparadise

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”.

Tags: BirdLife, Cousin Island, Nature Seychelles, Seychelles Magpie robin

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Category: Cousin Island, birds | Date: Jul 07 2009 | By: savingparadise

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.

Tags: Cousin Island, Herald Petrel, Jouanins Petrel, Seychelles

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Category: Cousin Island, Endemic birds, Seychelles Warblers | Date: Jul 02 2009 | By: savingparadise

Here is a YouTube video courtesy of Birdlife International called “The Story of Cousin Island”. The video was made during celebrations for the 40 anniversary of Cousin Island. Cousin Island was purchased by BirdLife in 1968 to save the last remaining population of Seychelles Warbler. 40 years later, according to Birdlife, “warbler numbers have risen by 300%, and the island has been transformed from a coconut plantation to a profitable Nature Reserve which greatly benefits local people and global biodiversity.

With thanks to Birdlife.

Tags: Cousin Island, Seychelles Warblers, You tube

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