Irregular Reproductive Cycles in the Tongaland Loggerhead Sea-Turtle, Caretta Caretta L. (Cryptodira: Chelonidae)

Abstract

The concept of sea-turtles exhibiting regular reproductive cycles is widely accepted. In Tongaland, Natal, after 12 years of research 2 122 female loggerhead turtles have been tagged and the recovery rate of tagged animals back on the nesting beaches has reached 50 %. From a sample ofthese recoveries it is clear that there is no regular reproductive cycle and thus that irregularity is characteristic of this population. The most frequent period of absence from Tongaland is two years but few animals repeat this absence cyclically. Results so far indicate that a loggerhead female can nest for at least four seasons spread over a period of at least nine years.