Adult and baby Aldabra tortoises on Cousin by Dailus Laurence
Nature Seychelles is currently mourning the loss of one of its Giant Aldabra Tortoises, Sir Henry, on Cousin Island Special Reserve. Although the death of this tortoise was due to old age, the recent wretched story from Curieuse Island in which a substantial number of baby giant tortoises were stolen, makes the loss on Cousin seem a little more disheartening.
Cousin Island is a marine protected area as well as an important bird area, and with the protection of this island under the Seychelles law, wardens on the island are vigilant in making sure that no wildlife is taken from the land or the 400 meters of water around the island.
Tourists taking photos of one resident giant tortoises on Cousin photo by James Luxton
The relatively small size of the island makes the task of patrolling easier for the staff who regularly try to ensure nothing leaves or enters this fragile environment.
The tortoises on Cousin are a favourite especially for the international volunteers who come and work on the island. The tortoises come out to feed in the warmth of the morning sun and in the afternoons find a shady spot or water pond to cool off. There are countless photos of volunteers and tourists with these tortoises, one of the most primitive reptiles which still survive on earth.
Braving the mosquitoes for tortoise census
“Although the loss of one of our tortoises is sad for the staff and volunteers who know them intimately and sometimes by name, this is nature just taking its course. It will decompose and some other creatures will feed on it,” says Eric Blais, Nature Seychelles’ Island coordinator. “I would be more upset if somebody stole a tortoise because we have worked very hard to get the population to where it is now.”
The Giant Aldabra tortoise was introduced on Cousin Island from Aldabra somewhere in the early 1900s. Once a year, from July to August the staff on Cousin carry out a census as part of the monitoring work of the population of giant tortoises on the island.
From the last census, it is estimated that there are 75 tortoises on the island – 22 male and 11 female, and numerous juveniles whose sex cannot be determined until they become adults. All of the tortoises are tagged which helps to identify them. When a tortoise is encountered, the length and width of the carapace is recorded as well as if it is a male, female or unknown.
Trying to determine if this giant tortoise is male or female by the shape of its belly
“There is very little record of death rates of tortoises here because they can live well over a hundred years, and for all of us, the recent death of one of our giant tortoises is a first,” says Cheryl Sanchez, Nature Seychelles Science coordinator on Cousin. “In fact the very large old animals that stay in the grassy area around the research house are probably much older and very likely some of the original animals that were relocated to Cousin from Aldabra.”
The Aldabra Giant tortoise (Aldabrachelys gigantea ) is the only species of tortoise found in the Seychelles, and endemic (only found in the Seychelles). Like Nature Seychelles, several conservation organisations work hard to protect this unique reptile from extinction as was the case with the Mauritius Giant Tortoise which is now one only for the history books.