ROSTAL, D.C.*; LEBLANC, A.M.; DRAKE, K.K.; FRICK, M.; WILLIAMS, K.; BARNARD-KEINATH, D.; ROBINETTE, J.; LANCE, V.A.; Georgia Southern University, Statesboro; University of Alabama at Birmingham, Birmingham; Georgia Southern University, Statesboro; Caretta Research Project, Savannah; Caretta Research Project, Savannah; U.S. Fish and Wildlife Service, Savannah; U.S. Fish and Wildlife Service, Savannah; San Diego State University, San Diego: Reproductive Physiology Of Loggerhead Sea Turtles (Caretta caretta) Nesting On Two Georgia Barrier Islands: Understanding Population Patterns And Fecundity

The nesting physiology of the loggerhead sea turtle (Caretta caretta) was studied on two Georgia barrier islands from 2000-2005. Nesting activity was monitored from early May until early August on Blackbeard Island and Wassaw Island. All nesting females observed were measured, double flipper tagged and given a PIT tag in the right flipper. Blood samples were collected from nesting females for hormone analysis each season and the reproductive status of a subset was determined by ultrasound. Nesting chronology based on tag information was correlated with hormone and ultrasound results. Testosterone and estradiol levels showed gradual decline across the course of the nesting season. Progesterone levels fluctuated as observed in other species. Corticosterone levels increased towards the end of the nesting season. Females nesting in Georgia have been documented to lay up 7 clutches of eggs during the nesting season. Yearly variation in nesting and movements between barrier islands have made accurate determination of fecundity difficult. Our results demonstrate that females are laying 5.4 nests per nesting season. This represents a 20% increase in fecundity over that previously reported in the literature for this species. Seasonal nesting patterns and fecundity measures will be discussed.