LTREB: Long-term Research on Environmental Gender Determination in a Model System (Chrysemys): the Next Five Years

Iowa State University, Ames IA

Investigators

Abstract

In several major groups of vertebrates, environmental temperatures experienced during embryonic development determine offspring sex. Temperature-dependent sex determination (TSD) will be addressed with a multi-year field study of a wild population of the painted turtle, Chrysemys picta. The project will investigate several aspects of this unusual phenomenon: (1) the impact of long-term climatic variation on population structure, particularly the ratio of males to females, (2) the effect of lifetime patterns of nesting behavior on offspring sex ratio, and (3) climatic effects on variation in predator numbers and differential predation on nests, and hence shifts in population sex ratio. A team of student researchers will record nesting date and vegetation cover over nests, follow females across years to evaluate nesting behavior, monitor nests to investigate the influence of predators on offspring recruitment, and relate these data to information on climate. The findings of this research will have important implications for the impacts of climate change and human habitat use on the biology and conservation of species with TSD. This long-term research program will also continue to provide extensive educational opportunities for numerous students (including underrepresented minorities and women) and the public.