A major goal of avian ecologists has been to quantify and explain patterns of species co-occurrence and community structure. Until recently, most emphasis in this area was placed on birds at temperate latitudes during the breeding season. However, because species may be subjected to the most stringent selective pressures during the nonbreeding seasons (winter and migration), ecologists in the 1980s have emphasized a year-round approach to the study of bird community structure and foraging ecology. In addition to those theoretical considerations, the unfortunate destruction of native tropical vegetation creates a need for immediate action to assess effects of habitat alteration on overwintering migrant and resident bird species. This study investigates a number of unresolved problems in neotropical bird ecology on wintering grounds and in migration. Specifically, effects of: (1) vegetation structure, (2) food resources, (3) presence of hetero- and conspecifics, and (4) season on the foraging ecology of and habitat use by migrant wood-warblers in Belize, Central America, and Tennessee will be assessed. Simultaneous quantification of the above variables will provide insight into their effects at the individual, population, and community levels. Integration of these results can elucidate the year-round ecological constraints imposed on populations of migrant neotropical birds that breed in temperate areas.
