Control of Reproductive Function in Diverse Habitats

University Of Washington, Seattle WA

Investigators

Abstract

This proposal will investigate the environmental control of breeding in populations of "crowned sparrows" of the genus Zonotrichia. Key populations have been identified in Arctic, mid-latitudes and equatorial regions that express the full spectrum of extreme inflexibility of timing (Arctic) to varying degrees of flexibility and asynchrony at mid-latitudes and equatorial regions. Field experiments will determine how flexible breeding seasons are within each habitat. Particular emphasis will be placed on how social interactions within and between sexes contribute to the synchronization and temporal organization of the breeding cycle. Parallel laboratory experiments will explore further how environmental signals such as change in day length, temperature, food and water interact with social cues to regulate neuroendocrine and endocrine secretions that orchestrate reproductive function. Of particular importance are investigations of novel peptides in the hypothalamus that may provide pathways for these environmental signals. The results will have practical applications for how vertebrates may respond to global change in the near future, and will provide unique insight on how environmental control mechanisms evolved. Some populations may be able to adjust, whereas others may not, possibly indicating where future conservation efforts should be focused. The project will provide a framework for education at undergraduate and graduate levels, as well as for outreach to an ongoing project with a local high school.