Breeding Biology and Conservation of Hawksbill Turtles, Eretmochelys imbricata, on Cousin Island, Seychelles

Diamond, A

A two-year tagging program on Cousin Island, Seychelles showed that Hawksbills nested between September and March, each female nesting on average four times at intervals of 15 to 18 days. Females did not nest in successive years but the number of years between breeding attempts is not known. Twenty to thirty females now nest each year; the number of nests has increased markedly since the island became a nature reserve in 1968. Some females tried to nest on other islands in the same season, although those returning to Cousin usually did so within 50 m of their previous nest. The average clutch was 182, the largest recorded for any sea turtle, and the maximum estimate of average nest success was 86 %. Present exploitation in the Seychelles is unsound from both biological and sociological points of view, exploiting the vulnerable breeding stock for a luxury product ('tortoiseshell') while wasting potentially valuable protein. It is recommended that future policy should concentrate instead on harvesting eggs for human consumption, while totally protecting adults, thus diverting valuable protein from natural predators to the local human population. This policy would exploit the stage of the turtle's life cycle best adapted to sustain high losses with minimum effect on breeding stocks, to the mutual benefit of turtle and local human populations.

Breeding Biology and Conservation of Hawksbill Turtles, Eretmochelys imbricata, on Cousin Island, Seychelles

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