In 1983-84 we studied home ranges, daily flight activity, and habitat use by black (Coragyps atratus) and turkey vultures (Cathartes aura) in the mixed farmland of southern Pennsylvania and northern Maryland. We radiotagged and tracked 11 black and 10 turkey vultures for 270 days. Black and turkey vultures had mean home ranges of 14,881 and 37,072 ha, respectively. Home ranges overlapped and we saw no territorial defense. Turkey vultures had larger variation in 6-month home-range size than did black vultures. Home ranges of both species contained a greater proportion of roads and open habitat than the entire study area. Black and turkey vultures used forested habitats more than expected during all behaviors except feeding. Black vultures reused feeding sites more often than turkey vultures. Habitat containing no buildings was used for perching and nest sites. Most roosts were used only 1 night but a few frequently used roosts supplied most roosting. Both species reused roosts most often in winter. Habitat used for nest sites was roadless, forested, and undeveloped. Nest sites were all in rock crevices. Successful nests were farther from buildings than were unsuccessful nests. Human disturbance and canid predation may be significant causes of nest failure. Inter- and intraspecific minimum internest distances were <125 m. Vulture numbers can be managed by manipulation of roost, nest, and feeding site quantity and quality.
引证/输出
预览资料
文章 : 英语