Another year, another turtle season come and gone on Cousin Island Special Reserve. Turtle season is organized chaos. It is nonstop beach patrols from sunrise to sunset come rain or shine. There is no other experience quite like working a full turtle season in the Seychelles which is very different from any other place I have been stationed, not to mention on Cousin Island which is especially unique. Nowhere else in the world do sea turtles consistently nest throughout the day.
Cousin Island, a protected marine and terrestrial reserve managed by Nature Seychelles, has two very distinct wildlife seasons. During the South East (SE) monsoon season, the island is inundated by nesting seabirds. Although we get nesting seabirds year-round, during this time the Lesser and Brown Noddys arrive and take up every imaginable space on tree and rock to breed. If you sneeze while walking in the forest, chirping quickly radiates throughout the forest, making it almost impossible to hear the person next to you speak.
In October, the winds shift to coming from the North West (NW), and then comes turtle season. Cousin predominantly has Hawksbill Turtles (Eretmochelys imbricata), and on this small island we go big, we don’t just get a nesting turtle here and there. The island is the most important nesting site for Hawksbill turtles in the Western Indian Ocean.
One turtle track up and another down the beach
Looking back on the 2015/2016 turtle season, there are some memorable moments such as the turtle that came to us - she crawled up the beach and nested next to the kitchen of the Research House as we were cooking dinner. Then there’s our solar powered turtle which nested under the solar panels, as we sat at the Research House having our morning coffee. There was another rather anxious turtle that dug and abandoned FIVE egg chambers and finally decided to nest two hours after we had initially spotted her, in a mosquito infested area.
One of our volunteers was sitting behind a nesting turtle and counting her eggs when a nest hatched right next to where she was and Hawksbill hatchlings crawled on both sides of her in order to get to the ocean. Another amusing moment was when a volunteer was counting the eggs of a turtle nesting under one of the visitor shelters, and a tortoise parked next to him watching the whole process.
The eggs are counted as they drop into the nest
Sea turtles are generally charismatic creatures. In order to reproduce, they have to go on land. They have to crawl on the sand and with their back flippers dig an egg chamber and after laying over 100 eggs, cover it all up before going back to the ocean. To top that off, they do this multiple times in one season! When on land, they seem awkward and clumsy, but the dexterity of their back flippers while digging an egg chamber is mesmerizing. Yet when they are underwater they are amazingly gracious swimmers in spite of their large shells.
Seeing nesting turtles on Cousin, it is hard to imagine this species is in danger;; however they are, owing to the fact that they are slow-growing, late to reach sexual maturity, and are very vulnerable to various threats such as pollution, habitat loss, poaching, and so forth. In order to understand whether the population is increasing, decreasing or stable, you have to analyse data collected over several years.
According to a published scientific paper, the hawksbill nesting population on Cousin increased 8-fold between 1972 and 2009. This does not mean that the Hawksbills are in the clear and that they should be taken off this endangered list. It does mean that the protection afforded to them may be working, and more of this data collection is needed in making management decisions for their protection.
The 2015/2016 season saw a similar number of nests as those seen in the past three seasons, and with the help of Nature Seychelles’ international volunteers, approximately 86% of these nesting turtles were encountered as they came up to the beach to lay and those that needed to, were tagged on their flippers. This allows us to build an “inventory” and a history of the females who use the beaches of Cousin Island.
For me coming across several turtles as they emerged from the water and headed for the beach to search for the perfect spot to lay the next generation of Hawksbill turtles on my birthday, on Christmas day and on New Year’s day was the best gift I could have asked for.
by Cheryl Sanchez, Nature Seychelles’ Science Coordinator - Cousin Island Special Reserve