Life History Evolution in Northern Versus Southern Regions: A Comparative Field Study

University Of Montana, Missoula MT

Investigators

Abstract

This project is designed to distinguish among four competing hypotheses addressing clutch size variation in birds nesting in northern and southern hemispheres. The PI will use comparative and experimental methods to test whether nest predation, food limitation, density, or adult mortality--and possible interactions--are important factors in affecting clutch size in birds. Eight pairs of species matched for phylogeny and ecology in Arizonan, Argentinan, and Venezuelan forests will be observed with controlled comparisons of species between tropics, north and south temperate forests. Tests will include detailed measurement of life history traits (clutch size, numbers of broods, renesting effort, length of time between renesting attempts, nest predation rates, adult survival, incubation behavior, and nestling feeding rates) of coexisting bird species among sites to differentiate among the alternative hypotheses.