Welcome to the American Ornithological Society 2018 Annual Conference. We are pleased to have you join us at the lovely Hilton El Conquistador Resort in Tucson, AZ.
Many animals with genetic sex determination are capable of manipulating sex ratios via behavioral and physiological means, which can sometimes result in fitness benefits to the parent. Therefore, revealing the mechanisms for altered sex ratios in vertebrates remains a compelling area of research. Sex ratio manipulation in birds is not widely documented, and the ability of wild birds to alter sex ratios post egg-laying has largely been overlooked or thought unlikely. Incubation temperature is a key component of the developmental environment for birds, but despite its well-documented effects on offspring phenotype it has rarely been considered as a factor in avian sex ratios. Using ecologically relevant manipulations of incubation temperature within the range 35.0–37.0°C, we found greater mortality of female Wood Duck (Aix sponsa) embryos during incubation than males regardless of incubation temperature, and evidence that more female than male embryos die at the lowest incubation temperature (35.0°C). Our findings in conjunction with previous work in brush turkeys suggest incubation temperature is an important determinant of avian secondary sex ratios that requires additional study, and should be considered when estimating the impact of climate change and other human disturbances on avian populations.
