Tortues imbriquées à Nosy Be

Species Hawksbill turtle in Nosy Be

The Hawksbill Turtle, the only representative of the genus Eretmochelys, is a species of turtle in the family Cheloniidae. In French it is also called Tortoise with scales or Tortoise with beak of falcon. It is also locally called Karet or Carette, especially in the West Indies, Mayotte or Reunion. However, these names are confusing with the Loggerhead Turtle (Caretta caretta).

It is distinguished by several unique anatomical and ecological characters; It is easily identifiable by its thick scales posed like the tiles of a roof, by its long, narrow and hooked beak and by the two claws arranged a few centimeters from each other on the outside with mid-fins.

It lives near the coast in all tropical seas. Renowned and long sought after for the superior quality of its scales, it is for this reason one of the species of sea turtles most endangered.

Hawksbill turtles live year-round in the reefs around Nosy Be. The best known spot to meet them is the Nosy Tanikely marine reserve, where we organize snorkelling trips.
The hawksbill turtle measures between 60 and 100 cm and weighs between 43 and 75 kg, the largest specimen found was 127 cm. The eggs measure between 30 and 45 mm and weigh between 20 and 31.6 g.

The observation conditions being difficult, the feeding of turtles at sea is not very well known; it is believed that they must feed mainly on jellyfish.

In the benthic zone, and more particularly in coral reefs, they mainly consume sponges. In the Caribbean, the latter constitute 70 to 95 % of their diet and, like many spongivores, they consume only specific species of the class of Demospongiae, and more specifically those belonging to the orders Astrophorida, Spirophorida and Hadromerida . It is the only known spongivore reptile.

Les tortues imbriquées femelles ne se reproduisent que tous les deux ou trois ans. La période de reproduction durant six mois, la femelle retourne sur son site de nidification en moyenne de 2 à 4 fois par saison. Chacune débarque sur la plage et creuse un nid et elle y dépose en moyenne une centaine d’œufs. La période d’incubation est de 47 à 75 jours, selon la saison et l’emplacement.
On pensait à tort, jusqu’à récemment, que la tortue imbriquée était moins migratrice que les autres espèces de tortues marines. Des études utilisant la télémétrie satellite ont montré que cette espèce voyage sur des milliers de kilomètres. Il est probable que les tortues imbriquées s’alimentent et se multiplient dans des zones complètement différentes.

Où observer les Tortues imbriquées à Nosy Be ?