9623556 Moore The complexity of bird migration derives from a wide array of factors. Physiology, behavior, ecology, and the physical environment shape and constrain observable patterns of migrant spatial and temporal distribution, behavior, and ecology. The sum of these patterns can be considered the overall "migration strategy" for dealing with the challenge of seasonal long-distance movements. While a diversity of migration strategies exist among species of migratory birds, individuals of different ages or genders within a species also exhibit differences in migratory behavior. The question of how such within-species differences are mediated and why these differences occur is the focus of this award. The research will identify the causes and ecological consequences of differential migration of male and female intercontinental migratory songbirds. Two hypotheses will be tested: 1) differential migration is the direct result of male-female competition or has evolved as a means of eliminating such competition through divergent use of resources; and 2) differential migration is a result of gender-based variation in the costs of reproduction and survival. Findings will identify environmental factors that facilitate successful migration in songbirds. In so doing, the research will contribute to the management and conservation of songbird populations and biodiversity. As bird species exert strong controls over insect pest populations in some forest ecosystems, research aimed at their conservation has implications for the integrity and health of forest resources.
