The Northern Goshawk:
Future Endangered Species?

M. Lynne Corn 1
Specialist in Natural Resources Policy
Environment and Natural Resources Policy Division

June 29, 1994

94-534 ENR

COMMON NAMES: Northern goshawk, goshawk

SCIENTIFIC NAME: Accipiter gentilis. Many scientists recognize 12 subspecies of the northern goshawk, 3 of them in North America: A.g. apache, A.g. laingi, and A.g. atricapillus.

CURRENT RANGE: Forested areas all around the northern hemisphere. The three North American subspecies are found in the following areas: A.g. apache in the mountains of southern Arizona and New Mexico, and south through the Sierra Madre of Mexico; A.g. laingi (Queen Charlotte Islands goshawk) in coastal British Columbia and southeastern Alaska; and A.g. atricapillus throughout northern North America, and south through the western states to Arizona and New Mexico, which, during winter, expands its range substantially into central and eastern states.

LEGAL STATUS: The species is a Candidate (Category 2) for listing under the ESA throughout its range in North America (56 FR 58804).

HABITAT: Northern goshawks are found in coniferous, deciduous, and mixed forests. For foraging and nesting, northern goshawks depend on forests that have a high density of large, old trees and high overstory canopy. Nests tend to be found near a source of water and on moderate north-facing slopes. They nest on horizontal branches of trees (e.g., birch, beech, juniper, pine, spruce, and fir) often close to roads, swamps, or other forest openings. Older forests are required as the northern goshawk needs large trees for its bulky nests and requires space in and below the canopy to pursue and capture prey. Because the birds have large home ranges they tend to favor sizable stands of forests, with a reported home range of approximately 6000 acres.

PRINCIPAL AFFECTED FEDERAL AGENCIES: Bureau of Land Management (BLM), U.S. Forest Service, and U.S. Fish and Wildlife Service (FWS).

MAJOR THREATS: A variety of experts point to numerous threats. These include: forest management practices that reduce overstories or permit advanced development of understories, such as timber harvesting, fire suppression, and livestock grazing, as well as drought, disease, prey reduction, and toxic chemicals.

BACKGROUND: Northern goshawks are one of the largest of North America's hawks, ranging from 19-27 inches long with a wingspan of 40-47 inches. This bird of prey has short, rounded wings and a long tail. Such adaptations permit the bird to maneuver rapidly through dense cover in pursuit of its prey. (Some biologists call the northern goshawk the "sports car of the bird world.") Northern goshawks typically feed on hares, rabbits, squirrels, crows, smaller hawks, owls, woodpeckers, and a variety of other avian and mammalian species.

In 1982, because of concerns over the effects of timber harvesting on the hawk, the northern goshawk was listed as a "sensitive species" on all National Forest System lands in Arizona and New Mexico by the Southwestern Region of the Forest Service. Though obligations of the Service are not clearly defined when a species is considered "sensitive", the Service does give consideration to the species when planning projects, to carry out its responsibility to maintain viable populations of native vertebrates.

In June 1991, the Regional Forester issued management guidelines for conservation of the northern goshawk in the Southwest Region. These were temporary guidelines to be used while data were collected about the hawk. Timber harvesting, and other activities, was to be continued in goshawk habitat in the region during the review.

In July, perhaps partially disappointed by the guidelines issued by the Forest Service, a coalition led by Maricopa Audubon Society in Arizona petitioned to list the northern goshawk as endangered in Utah, Colorado, New Mexico, and Arizona. The FWS, after reviewing the petition, declined to list the species, since it concluded that northern goshawks in those regions did not form a distinct population. Under the Endangered Species Act (ESA), vertebrate populations can only be listed if they are determined to be distinct.

In September 1991, the same group re-petitioned for listing, this time requesting that listing for northern goshawks in the "forested west" (defined by the petitioners as the forested United States west of the 100th Meridian). The FWS arrived at the same conclusion and again refused to list the species. However, in January 1992, the agency elevated the species to Candidate (Category 2) level. Category 2 species are those which show some indication for vulnerability, but lack sufficient data to warrant listing. The agency launched a status review seeking to obtain information relating to the possibility of distinct population segments within the range of the northern goshawk in North America. The Southwest Region of FWS assumed lead responsibility in the review. At this time no summaries have been published.

CONTROVERSIES: If the northern goshawk, under the ESA, is listed as endangered or threatened, timber harvests may be reduced in a number of States, especially in the west.

UPCOMING EVENTS: In May 1994, the Independence Mining Company announced plans to fund a study to determine the effects of mining activities on northern goshawk populations at its Jerritt Canyon mine in Nevada. This study will be conducted by a Boise State University graduate student and should be completed in 1997. The Forest Service will use the information gathered to help determine land management policies in the area and will pass the data on to the FWS.

On May 2, 1994, a coalition of environmental groups led by the Southwest Center for Biological Diversity (in Silver City, New Mexico) announced their intention to sue the FWS if the agency fails to act within 60 days to list the northern goshawk as an endangered species in the "forested west". On May 9, a similar coalition of environmental groups led by the Southwest Center for Biological Diversity and the Greater Gila Biodiversity Project submitted a petition to list the Queen Charlotte Islands goshawk as endangered. This subspecies is found in old-growth coastal rainforests in southeast Alaska and coastal British Columbia. The coalition blamed logging in the region for the decline of the subspecies. The U.S. Forest Service recently listed it as sensitive in the region.

In June 1994, local conservation groups in Arizona indicated they question the FWS conclusion on the second petition that was filed for listing of the northern goshawk in the "forested west", and therefore may introduce a third petition to FWS.

References

1 Under the supervision of M. Lynne Corn, Cynthia Marcum, B.Sc. candidate at Bowling Green State University, researched and contributed to this report.