A review of home range sizes of four raptor species of regional conservation concern

Knowledge of the home range size (HRS) of species is critical for their effective management and conservation. We systematically searched the open literature for information on HRS for Bald Eagle (Haliaeetus leucocephalus), Golden Eagle (Aquila chrysaetos), Prairie Falcon (Falco mexicanus), and Ferruginous Hawk (Buteo regalis). We found 24 articles with HRS estimates and accompanying methodology and demographic information on sampled individuals. Most studies focused on Bald Eagles, followed by Golden Eagles, Prairie Falcons, and Ferruginous Hawks. HRS estimates for the Golden Eagle were the largest and had the greatest associated variance (mu = 8797 km(2); 95% CI, 0-47,284 km(2)). Estimates for Bald Eagle HRS were smaller, with a mean of 2215 km(2) (95% CI, 0-12,472 km(2)). Prairie Falcon and Ferruginous Hawk HRS estimates were much smaller, with means of 156 km(2) (95% CI, 0-415.22 km(2)) and 22 km(2) (95% CI, 0-96.88 km(2)), respectively. HRS estimates varied substantially across period (breeding/nonbreeding), sex, age class, fix type, and estimation method for all species, and this finding points to the importance of accounting for the context of these estimates. The information can be used to inform other efforts to characterize the spatial use of these 4 raptors.