Ecological and physiological correlates of migration and dispersal in birds

点击翻译按钮获取中文摘要

I will investigate habitat characteristics associated with the maintenance of source vs. sink populations of migratory passerine birds. This will involve the use of stable isotope markers (primarily deuterium, carbon-13, nitrogen-15) and trace-element profiles in feathers as measures of previous breeding or natal location. Bird feathers represent ideal material to use as proxies for location since they are grown during known periods of the life cycle and maintain isotopic signatures of source. By investigating the isotopic signatures in feathers of populations of individuals, the composition of those populations as local vs. more long-distance dispersers can be derived. Optimal forest sites will be contiguous boreal forest tracts of large extent and poor forest will be isolated forest fragments surrounded by agriculture. Thus, the role of habitat quality in site philopatry and dispersal will be tested. The second primary area of research will be the investigation of factors influencing the relative input of endogenous lipid and protein reserves into reproduction in several species of high-Arctic nesting birds varying in body size (large-bodied waterfowl through small-bodied waders). Stable isotopes represent a powerful tool to trace origins of nutrients directly. My new research will pursue this question further by testing the plasticity of the income vs. capital strategy in shorebirds subjected to different spring conditions across a latitudinal gradient in the Canadian Arctic.