Demographic and behavioral comparisons of suburban and rural American Crows

摘要: American Crows (Corvus brachyrhynchos) have become common suburban and urban birds in the last 50 years, using these environments for roosting breeding. I studied crows upstate New York from 1989 to 1999, compared reproductive success, survival, social behavior of rural areas. Although both maintained permanent territories, had smaller territories nested at higher densities. Both periodically left their fall winter join foraging aggregations roost night. The proportion nests attended by auxiliaries did not differ, but were larger families. Overall nest success was Success rates during egg stage cycle differ between habitat, nestling cycle. Survival post fledging better areas, after one year annual survival habitats. Birds raised habitat tended breed same habitat. clutch sizes hatchability habitats, produced nearly more young per successful significantly than crows, suggesting that food resources Data a drought year, time apparent shortage, suggested also less dependable those increase over 25 years eastern North America may be due part exploitation nesting