PARK, A.; WIBBELS, T.*; VEGA, L.; LIRA, D.; ACOSTA, R.; PENA, J.; BURCHFIELD, P.; SCHROEDER, B.; Univ. of Alabama at Birmingham; Univ. of Alabama at Birmingham; Gladys Porter Zoo, Brownsville, TX; Gladys Porter Zoo, Brownsville, TX; Gladys Porter Zoo, Brownsville, TX; Gladys Porter Zoo, Brownsville, TX; Gladys Porter Zoo, Brownsville, TX; National Marine Fisheries Service, Silver Springs, MD: Validation of Temperature-Based Methods for Estimating Hatchling Sex Ratios in the Kemp’s Ridley Sea Turtle

Like all species of sea turtle, the Kemp’s ridley possesses temperature dependent sex determination. This type of sex determination can potentially produce a wide array of sex ratios. Therefore, it is of ecological and conservational importance to monitor the hatchling sex ratios produced in nesting beach conservation programs. The Kemp’s Ridley Conservation Program relocates the majority of nests into protected egg corrals at the main nesting beach of the Kemp’s ridley near Rancho Nuevo, Mexico. The purpose of the current study was to use histological analysis of hatchling gonads to validate the use of nest incubation temperature as a method of estimating hatchling sex ratios. Nest incubation temperatures were monitored with data loggers and sex ratios were predicted based on the average incubation temperature during the middle third of incubation during the 2000 and 2002 nesting seasons. Dead hatchlings were collected from freshly excavated nests after live hatchlings had emerged during the 2000 and 2002 nesting season. Histological data corroborated the temperature dependent data. Collectively these data suggest the production of sex ratios with a female bias in the Kemp’s Ridley Conservation Program during each of the 2000 and 2002 nesting seasons.