Meeting Abstract

107.1  Tuesday, Jan. 7 08:00  Temperature, Moisture and Male Production in Marine Turtle Nests… Oh What a Maze WYNEKEN, J; LOLAVAR, A; TEZAK, B M*; Florida Atlantic University; Florida Atlantic University; Florida Atlantic University jwyneken@fau.edu

The incubation environment determines the sex of marine turtles and temperature is the major factor thought to direct sex determination. In nature, most marine turtle hatching sex ratios are samples are limited in size and in the numbers of mothers represented. Sex ratios often are inferred temperature-sex ratio response curves derived in lab studies. The relationship between the temperature and sex ratio response is reasonably well documented in controlled temperature studies, yet typically the numbers of clutches and samples are limited. In the field, the temperature-sex ratio relationship differs from that in the lab so that female biased sex ratios are common at male-producing temperatures and male-producing temperatures are rare or do not occur in many field situations. Here we identify key uncertainties left by previous studies lab studies of sea turtle sex ratios based solely on incubation temperatures. We describe our large, multi-year field-based incubation temperature-sex ratio results and the sex ratio results of a series of controlled temperature and moisture conditions using a reasonably large numbers of nests samples. Both sets of studies suggest that high humidity modifies sex ratio responses of marine turtle eggs incubated near pivotal temperatures so that male-biased sex ratios occur more frequently. Both temperature and humidity can influence the sex ratios in experimental nest conditions so that normally female-biasing temperatures can produce male-biased sex ratios in high moisture conditions.