Saving Paradise

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: birds | Date: Aug 31 2009 | By: savingparadise

A Frigatebird rescued from the harbour was brought into our office today. It seemed unable to fly. Frigatebirds, abundant throughout Seychelles and breeding on Aldabra and nearby islands, are long-distance fliers that spend most of their life flying over the ocean with a gliding flight. However, they do not land on sea. Unlike other seabirds, the feet are not webbed, making it difficult for them to paddle through water. Their feet are also too small and do not give the bird the force needed to become airborne from the surface of the sea. For food, Frigatebirds pick prey from the water surface. They also snatch fish from other birds in the air. For seabirds, they have poor water proofing. We think the reason our bird will not fly is that it got a bit of water in its wings. No injuries were visible.

We took the bird  outside and attempted to perch it on the mangroves, popular with Frigatebirds for nesting, but it was incapable of balance.

In the end, we decided the bird hide would be best for it to rest and recover. It is currently patched there where it has a great view.

The bird hide is the place where visitors to the wetland [Sanctuary at Roche Caiman] get the opportunity to view birds. It’s a nice place at the end of a boardwalk. Visitors to the hide are asked to observe these rules:
-    Stay quiet
-    Do not tamper with displays in the hide
-    Hold on to your litter or take it to the nearest bin
-    Smoking and chewing gum are strictly prohibited.

Somehow I don’t see the Frigatebird having any trouble with these rules. All the same we hope it will leave the hide and return to its long distance gliding.
More Frigatebird facts at our website

Tags: Aldabra, Frigatebird, Seabirds

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Category: Seabirds | Date: Jul 13 2009 | By: savingparadise

Paradise, am afraid, is slightly wet. The south east monsoon season is here and it’s been accompanied by some rain. I have been surprised to wake up to a cloudy morning and cooler temperatures. I even spotted one or two souls walking around in sweaters! The hills on Mahe look stunning in the early morning mist, and can stay that way throughout the day.

This is also the breeding season - starts May to October - for many seabirds and is therefore the best time to see them. The Sooty Tern or golet in Creol is the best known as their colonies number in the millions. The Sooty Tern colony on Bird Island for example where Nature Seychelles has helped the owners previously is spectacular and attracts many local and foreign tourists.

 Saying hello to an old friend on Bird Island

However, many species such as the Fairy Tern and White tailed Tropic Bird remain outside the breeding season. On Cousin Island for instance its so easy to spot stunning Tropic Birds with their chicks nesting on the ground at the base of trees all year round that people are astonished by the tameness of the birds. Young tropic birds are cute and fluffy like this one below and as Cousin is predator free, and the birds are not used to harassment, it’s quite easy to approach them and take pictures.

This White tailed Tropic Bird chick is not camera shy

Seychelles small islands are nesting grounds for about 12 species of seabirds. During the breeding season species like the Lesser Noddy and Sooty Tern form large breeding colonies, with many thousands of birds all breeding at the same time in the same location. Before people settled on the islands of Seychelles, nesting sea birds were found on all of the islands. Killing by humans, nest disturbance and the introduction of predators like rats and cats have have now limited breeding. Some species like the Wedge tailed Shearwater or fouke in Creole, only breed on predator free islands such as Cousin and Aride.

Sooty tern eggs are prized in Seychellois cuisine but in the past over exploitation has ruined many colonies. Now the harvest is controlled although poaching still occurs. This year, 2009, the government decided not to harvest any eggs.

The monsoon also brings with it rough seas. Traveling by boat can be uncomfortable, terrifying or exhilarating depending on who you are. On Cousin, the landing site has been moved to a more suitable area on the North. Because of poor visibility and bad sea conditions activities on reef monitoring have been scaled down.

Read about the different species of  Seabirds on our website here and the work of the Seychelles Seabird Group coordinated by Nature Seychelles here.

Tags: Seabirds, Seychelles, south east monsoon

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