Meeting Abstract
The recovery of threatened or endangered organisms is complicated by the need for simple and effective methods of quantifying individuals. If the organism is difficult to access, its behavior is elusive, or some individuals are widely observable and others are cryptic, a census count is inadvisable. Sex ratios, population size, and relatedness of individuals are important metrics of population status, but if the organism is mysterious, these questions can go unanswered. For marine turtles, hatchling sex ratios are determined through patterns/proxies of temperature sex determination (TSD) and in Florida these mostly result in a female bias. Adult sex ratios typically differ from those estimated for offspring and so adult sex ratios are primarily estimated through counts of nesting females. This method, unfortunately, leaves the number of adult males to be enigmatic. Alternative assessment techniques include using molecular markers to identify parentage of individuals as well as fundamental relationships among males and females within a population. By using exclusion analysis (comparing maternal genotypes to offspring genotypes), male numbers can be estimated with greater accuracy, and those results can be applied to estimate effective population size. We compare the numbers of males and females contributing to a loggerhead sea turtle (Caretta caretta) nesting assemblage in southern Florida and determined that these turtles are promiscuous. However, we did not find repeating males, suggesting that the number of successful males may be higher than previously expected. In a species that has TSD and highly female biased hatchling sex ratios, this high occurrence of multiple paternity in a small nesting assemblage could signal an evolutionary shift to stabilize population sex ratios even as temperatures continue to rise.
