Migratory Pathways, Timing, and Home Ranges of Southern Greater Yellowstone Osprey

Bedrosian, Bryan; Cain, Steven; Wolff, Susan; Craighead, Derek

Recent advances in satellite telemetry have facilitated multiple studies of migratory patterns and movements of raptors. Despite the many published studies outlining migratory routes and overwintering areas of North American raptors (e.g., Martell et al. 2001, McIntyre et al. 2008, Mojica et al. 2008, Mandernack et al. 2012), most existing knowledge is regional and species-specific. Although some raptor species have clearly defined and centralized wintering areas regardless of breeding location (e.g., Swainson’s Hawk [Buteo swainsonii]; Kochert et al. 2011), it is more common for individuals from a species to have dispersed winter ranges (e.g., Brodeur et al. 1996). Long-distance movements of Ospreys (Pandion haliaetus) have been studied extensively. Old World studies of migration include investigations of timing, routes, orientation, and fidelity (Kjellén et al. 1997, Hake et al. 2001, Alerstam et al. 2006). Several studies have led to a near-complete view of Osprey migration routes in the eastern, central, and northwestern United States (Martell et al. 2001) but data from Canada and the Rocky Mountains are still lacking. Satellite tracking data from Ospreys in British Columbia indicate wintering areas along the western coast of Mexico, the Gulf Coast, and in Central America, but migration routes were not reported (Elliott et al. 2007). Satellite tracking in the United States has largely corroborated banding records (Poole and Agler 1987, Martell et al. 2001). Based on banding records, Ospreys originating from Saskatchewan and British Columbia winter along the Gulf of Mexico (Ewins and Houston 1992), whereas those from northern Idaho and eastern Washington winter along western Mexico and Central America (Johnson and Melquist 1991). The long-term maintenance of biodiversity and conservation of migratory species is dependent on knowledge of annual movements and management of habitats and threats within breeding habitat, but also along migratory pathways and wintering areas. Adult Ospreys spend ca. 6–8 mo away from their breeding areas and dispersing juveniles do not return for ca. 18 mo (Poole et al. 2002), making knowledge of nonbreeding ecology important for the conservation of this species. Here we report the migration movements of nine Ospreys from two nests in the southern Greater Yellowstone Ecosystem of northwestern Wyoming. Our objectives were to define migration timing, routes, and over-wintering areas for this population. We also report on family group dynamics of migration and home-range sizes of both breeding and wintering areas.

Migratory Pathways, Timing, and Home Ranges of Southern Greater Yellowstone Osprey

Collections