HATCHING AND EMERGENCE IN THE TURKISH MEDITERRANEAN LOGGERHEAD TURTLE, CARETTA-CARETTA - NATURAL CAUSES FOR EGG AND HATCHLING FAILURE

Hatching and emergence success were examined in 43 natural nests of th e Mediterranean loggerhead turtle (Caretta caretta) in the Gosku delta , Turkey. Overall clutch size averaged 90.3 eggs (range 42-151). Of al l eggs deposited, 58% hatched. In nine nests no hatching occurred, cau sed by repeated inundation in seven of these. In the successful nests, mean hatching success was 77%. Here egg failure was caused by microbi al infection, infertility, embryonic mortality, and developmental abno rmalities. Of all successfully hatched young, 18% failed to emerge fro m the nest. Straight carapace length of the hatchlings that failed to emerge was significantly lower than that of the successful ones. Emerg ence failure was highly correlated with a strongly compressed, solid b each sand type.