Volunteering on Cousin Island Special Reserve for Nature Seychelles Freya Blockley – BSc Zoology

Cousin Island I spent July and August of 2013 volunteering as a research assistant on Cousin Island Special Reserve. Cousin Island is a 27 hectare granitic island situated in the Indian Ocean along with another 114 other islands which make up the Seychelles. This island was once a coconut plantation but as the home to the 27 surviving individuals of the endemic Seychelles Warbler population, it was bought in 1968 by Birdlife International. In an attempt to rescue the warblers a habitat reconstruction programme was initiated; most of the coconut trees were cut down and the native vegetation was allowed to regenerate naturally. In 1969 Cousin Island became a nature reserve and it became more protected still when it became a Special Reserve in 1975. This reserve is managed by Nature Seychelles and includes the island and the surrounding sea up to 400m. It is now a home and important breeding site for many endemic and often endangered animals.

View out to sea from the highest point on Cousin at 69MASL

View out to sea from the beach

Life on the Island Living on this tiny island were 8 members of staff, 3 volunteers and 3 researchers. I was living in the research station along with the other volunteers and researchers. Each member of staff had their own house and these were distributed around the perimeter of the island, so as to deter illegal fishing in protected waters. There are no shops on the island and the water is not safe to drink. Therefore, several times a week, we would take the 20 minute crossing on the island boat to Praslin Island where we would collect food, water and fuel. Electricity on the island was run by a generator which was only on for scheduled hours in the day and water for washing was pumped from the well.

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The Research Station where I lived

Cousin Island

Working on the island Cousin is a very important breeding site for many species of seabirds and therefore one of my jobs was to monitor the activity of their nests to determine their breeding success. I was given 20 nests of 3 species of bird; the Brown Noddy, Lesser Noddy and White Tern. I visited these nests weekly to record the activity of each (whether it was empty, there was an egg, or there was a chick and if so how developed a chick it was). Other members of staff had nests to monitor so there were 100 in total for each species. This data will be collaborated to determine the breeding success for each species.

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Lesser Noddy nest with a parent and chick White Tern chick – the egg is laid directly onto a branch rather than in a nest

The Seychelles Magpie Robin is an endangered species and there are only 250 individuals. On Cousin there are 42 birds and these are tightly monitored. In small groups, consisting of a dominant breeding pair and several subordinate adults and juveniles, they occupy and defend a territory. Twice a week I would visit each territory and whistle to the birds. They would fly down at my call as they have associated it with you turning over a rock to reveal the invertebrates beneath it. As they fed I would record which individuals sighted (they can be identified by the colour rings on their left leg) and any behavioural observations. This regular monitoring ensures that there is an up to date record of the living birds, territory or hierarchy changes and nest observations.

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A group of Seychelles Magpie Robins defending their territory An attempt to catch a Seychelles Magpie Robin for re-ringing

I was also involved in carrying out the seabird, skink and tortoise census. Twice a year a seabird census takes place in an attempt to estimate and monitor population numbers of these birds. This involved visiting numbered plots and counting the number of each breeding pair (determined by the number of nests) of each species of sea bird within a designated area. Skinks are lizards and Cousin is said to have one of the highest densities of them worldwide. The skink census involved walking in 50m transects in designated plots and counting the number of both species (Seychelles Skink and Wright Skink) seen within a meter of the transect. There are free roaming Aldabra Giant Tortoises present on Cousin. We carried out a census in order to determine the number of individuals on the island. It involved systematically covering the island by foot, looking for tortoises. The tag number, location sited and biometric data were recorded for any tortoises seen. Any untagged were tagged with plastic number tags. Two years ago a census was carried out and only 35 tortoises were found. This year we managed to record 57 tortoises including 9 hatchlings which we were lucky enough to observe emerging from their underground nest. The hatchlings carapace measured 8.5cm by 9cm, compared with the largest tortoise’s carapace which measured 154cm by 157cm!

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Freshly emerged hatchling Aldabra Giant Tortoises Me with a Aldablra Giant Tortoise

Approximately 10,000 tourists visit Cousin every year. The island is open to visitors every week day morning and at 9.30 tour boats would gather just offshore. We then had to push our island boats out to bring visitors ashore. This is done to avoid any other boats landing on the island, so as to assure no pests are accidentally introduced. Cousin is free of rats, cats and dogs and this attributes much to the success of the breeding birds. I would welcome the tourist, answer any question and make sure they abided by the island rules until everyone was ashore and taken on tour by one of the wardens.

The wardens beaching the island boats after brining in tourists

Me ringing a Seychelles Magpie Robin chick

I learnt methods of bird capture such as mist netting and net catching and also how to ring birds, take biometric measurements and shown how to bleed a bird in order to take a sample for sexing. Other tasks included going into the forest and pulling up or cutting down invasive species of plants, patrolling the beach for turtle tracks, pumping the water, beach cleaning and raking paths.

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As well as work in the field, I spent some of my time working on the computer entering data from the surveys and monitoring. I was also given the role of going through all the previous population reports on the Seychelles Magpie Robin’s and extracting relevant data to write a history for each of the 42 individuals present on the island. This included details like date of birth, parents and territory or hierarchy change. Acknowledgments Without support from the Arthur Hoiser and Meyer Sassoon Travel Award, this trip would not have been possible for me. I would like to thank Louise Johnson and Mark Fellows for their support and the selection committee of this award for giving me the opportunity to travel to this beautiful island, learn many practical skills and techniques and give me a realistic perspective of life working in conservation which will all be valuable to me in the future. I would also like to thank Nature Seychelles and in particular April Burt for giving me the opportunity to volunteer on Cousin and providing me with such an unforgettable experience.

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