Ferruginous Hawk movements respond predictably to intra-annual variation but unexpectedly to anthropogenic habitats

Birds exhibit flexible movement responses to environmental variation across the annual cycle, and those responses can provide insight into potential impacts that environmental changes may have on these species. To understand year-round variation in space use by Ferruginous Hawks Buteo regalis, we tracked 12 birds breeding in southwestern Idaho, USA, using GPS telemetry collected over 207 bird-months. Home-range sizes of territorial adult hawks showed strong intra-annual variation, being smallest from April to June and largest from July to October. In contrast, juvenile birds (