Sand and Nest Temperatures and Sex Ratio Estimation for Loggerhead Turtle (Caretta caretta) Hatchlings on Göksu Delta

Abstract

Göksu Delta is one of the important nesting beaches for Caretta caretta (loggerhead turtle) in the Eastern Mediterranean coast of Turkey. In this study, temperatures of nests (n=10) and sand (n=4) were recorded by data loggers and results were examined to determine sex ratio of loggerhead hatchlings. Mean nest temperatures of whole period was 31.1°C that is higher than pivotal temperature of 29°C for Mediterranean loggerhead clutches, mean incubation duration was 51.7 days. The sex ratio of hatchlings of loggerhead turtle on Göksu Delta was estimated at 89.7% female based on temperature of whole period of incubation in nesting season of 2013. Results of estimation show that hatchlings sex ratio is highly female biased at study site.