THE PATTERN OF EMERGENCE BY LOGGERHEAD TURTLE (CARETTA-CARETTA) HATCHLINGS ON CEPHALONIA, GREECE

We examined the emergence pattern of hatchling loggerhead turtles (Caretta caretta) on the Mediterranean island of Cephalonia. Hatchlings usually emerged at night. Hatchlings emerged from each nest on more than one night (n = 10 nests, xBAR = 8.3 nights for emergence of all hatchlings, range = 5-11 nights). The number of nights over which hatchlings emerged increased as the distance of the nest from the sea decreased. Hatchlings did not always emerge as a single group from each nest on any night. When hatchlings emerged later in the night, the sand (depth measures = 3-15 cm) was cooler. This reflected the cooling of the sand during the night and suggested that there was no fixed sand temperature that initiated emergence. However, the time that the first hatchlings emerged each night was significantly correlated with the rate of change of sand temperature in the evening at 15 cm: i.e., when the sand at 15 cm cooled more rapidly in the evening, hatchlings emerged earlier.