Habitat use and time budgeting by wintering Ferruginous Hawks

Abstract

From 1992-1995 we studied the winter ecology of Ferruginous Hawks (Buteo regalis) in Colorado. Hawks spent 84% of the daylight interval perching. Time-budgets indicated that on average hawks perched 18 times day-1 (range 3-50), with perches averaging 30 min in duration. Diurnal perching was in trees, on poles, and on the ground. Utility poles and other human-made structures were used more than ground and deciduous tree perches. Tree perches were used for the longest mean duration. The mean daily Minimum Convex Polygon (MCP) home range of 36 hawks was 3.53 km2. The black-tailed prairie dog (Cynomys ludovicianus) was the most important prey species, and extant prairie dog colonies characterized winter habitat for Ferruginous Hawks.