Cooper Ornithological Society Annual Meeting, San Diego, CA, March 1996.
DEMOGRAPHIC COMPARISONS OF URBAN AND RURAL AMERICAN CROWS (Corvus brachyrhynchos). KEVIN J. MCGOWAN, Section of Ecology & Systematics, Corson Hall, Cornell University, Ithaca, NY 14853.
American Crows (Corvus brachyrhynchos) have been using urban environments for roosting and breeding in recent decades. I have studied crows in upstate New York since 1989, and compared reproductive success and survival of crows in urban and rural areas. Urban American Crows nested significantly earlier and at higher densities than rural crows. Nest success was equal between the areas, with similar success rates at each stage of the nest cycle. Survival of crows from fledging up to four years of age did not differ between the habitats. Group size and the presence of helpers at crow nests also did not differ. Rural nests produced one more young per successful nest and significantly larger young than urban crows, indicating that food resources were better in rural areas. Data from a drought year, a time of apparent food shortage, indicate that urban food resources also are less dependable than those in rural areas.