Preliminary Growth Models for Green, Chelonia mydas, and Loggerhead, Caretta caretta, Turtles in the Wild

Abstract

Capture-recapture measurements of 11 wild green turtles, Chelonia mydas, and of 28 wild loggerhead turtles, Caretta caretta, in Florida indicate that growth in straight-line carapace length fits von Bertalanffy growth models better than logistic models. The von Bertalanffy model for green turtle growth yields estimates for age at maturity of between 18 and 27 years, based on the carapace length of the smallest nesting female (88 cm) and the mean length of all nesting females (99 cm). The model for loggerheads yields estimates of between 12 and 30 years, also based on carapace measurements of the smallest nesting female (74 cm) and the mean carapace length of all nesting females (92 cm). It is suggested that the upper estimates provide more realistic indications of mean age at first maturity.