Breeding Season Diet of Northern Goshawks in Southeast Alaska with a Comparison of Techniques Used to Examine Raptor Diet

• Main Author: Lewis, Stephen B.
• Format: Text
• Language: unknown
• Published: ScholarWorks 2001
• Subjects: Ornithology; Accipiter gentilis; Northern Goshawk; Alaska
• Online Access: https://scholarworks.boisestate.edu/td/442; https://boisestate.on.worldcat.org/v2/oclc/48080122

A variety of factors influence a species' viability and survival (Lack 1954, Newton 1979). The availability and abundance of food, nest and roost sites, and cover, as well as processes such as predation and competition, all can act to limit populations. Understanding the processes of species limitation and the integral factors involved, is not only central to the study of ecology (Newton 1998), but forms the basis for practical wildlife management (Errington 1935, Litvaitis et al. 1994). While each of these factors plays a role in a species' ecology, there can be little doubt as to the fundamental importance of diet and feeding ecology (Newton 1979). In areas where nesting habitat is readily available, lack of food is often the limiting factor (Kenward and Widén 1989, Newton 1994). Populations of northern goshawks (Accipiter gentilis; hereafter goshawk) can be food limited during certain years or seasons (Widén 1989, Doyle and Smith 1994, Ward and Kennedy 1994, Dewey and Kennedy 2001). The link among goshawk prey species, the habitat they require, and the management of those habitats is recognized by the USDA Forest Service as a key element for conservation of goshawks and the biotic communities in which they occur (Reynolds et al. 1992, Iverson et al. 1996). Management guidelines for important prey of goshawks have been published for the southwestern region of the Forest Service (Reynolds et al. 1992) and other National Forest regions (e.g., Graham et al. 1999). Goshawks are large raptors that occur throughout much of the forested Northern Hemisphere (Squires and Reynolds 1997) where they nest (Reynolds et al. 1982, Crocker-Bedford and Chaney 1988) and hunt (Bright-Smith and Mannan 1994, Beier and Drennan 1997) in mature to old growth forests. The viability of goshawk populations in the western United States has been the subject of much debate recently (Kennedy 1997, Crocker-Bedford 1998) because of petitions to list the northern goshawk as threatened under the Endangered Species Act (Federal Register 1992, ...