Accipiter gentiles atricapillus & A. g laingi




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Northern & “Queen Charlotte” Goshawk (Accipiter gentiles atricapillus & A.g laingi) Global: G5 Provincial: S4B, S4N COSEWIC: n/a BC List: Yellow / Global: G5T2 Provincial: S2B COSEWIC: T (Nov 2000) BC List: Red Identified Wildlife



Distribution: The Northern Goshawk is an extremely secretive and elusive woodland raptor that avoids humans and human activity, contributing to its preference to nest in remote forested regions and areas with extensively forested canopy. Breeding territories typically are widely dispersed. Within the South Coast area two subspecies of the northern goshawk occur, A. g. atricapillus and A. g. laingi. The laingi sub-species, known as the “Queen Charlotte” goshawk is restricted to Vancouver Island, coastal islands and the west side of the Coast Mountains. Areas like Howe Sound and the Sunshine Coast are locations where it would most likely overlap with the more common mainland sub-species. Both sub-species occur in sparse populations with large territories and are heavily reliant on mature-to-old forest. The mainland sub-species breeds throughout the province.

Description: Height: 51-66 cm Wingspan: 1.1 m. Adults: A large and long-legged forest hawk, this species has a long narrow tail and relatively short rounded wings which allow it to move easily in the interior of forests. The head has a black crown, white eyebrow streak and red eyes. Adults typically have blue-grey dorsal plumage with a pale grey belly. Juveniles: Similar to other forest hawks with brown dorsal plumage and a dirty white-streaked belly and yellow eyes. Both sexes are similar, though as with other raptors the females are larger.

Diet: The northern goshawk forages during the day preying on medium sized forest birds (including upland game birds and songbirds) and small mammals (snowshoe hares, voles, flying squirrels, red squirrels). Prey preferences factors highly into goshawk distribution.

Looks Like? The largest of BC’s forest hawks (accipiters), the northern goshawk most closely resembles the Cooper’s hawk, and does overlap in range with this species. The Cooper’s hawk however like its smaller relative the sharp-shinned hawk easily adapt to more disturbed younger forests, including those in urban and rural areas. The Cooper’s does not have a white stripe above the eye. As well the dorsal and ventral plumage tends to be browner rather than the slate grey of the goshawk. Juvenile Cooper’s are hard to distinguish from those of the goshawk, other than by their size – Cooper’s hawks being smaller.

Primary Habitat This species is a mature forest and old-growth forest specialist preferring late seral conifer forests with open forest understory, high canopy cover, open forest floor, larger trees and natural edge habitats. Dense young second growth is avoided as the birds larger size requires more evenly spaced stands to maneuver through.

Secondary Habitat: While not typically found in disturbed areas, the northern goshawk will utilize maturing second growth stands (i.e. 100+ years old).

Critical Feature Nest are usually on slopes <30% and are composed of a large layering of sticks approximately 1m in diameter and 0.4m deep. Fresh sprigs of evergreen boughs line the interior. As with other accipiters, nests are usually located in the main fork of a tree, or the lowest branches below the canopy near the mainstem. Goshawks build multiple (3-9) nests and alternate amongst these nests in successive years. Habitat features: The presence of coarse woody debris, windthrow and downed snags, stumps, large and low thick-limbed trees are important structural features as they support main prey species.
Seasonal Life Cycle


Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec





Courtship/Breeding







Eggs laid/chicks in nest










Fledging/ Juveniles & adults begin over-wintering in the fall



















Habitat Guild Old growth and mature coniferous forests.

Threats

  • Fragmentation of forage areas and loss of preferred nesting features are considered the most significant threat.

  • Large-scale “clearcut” removal of forest cover is felt to adversely affect the viability of respective populations.

  • Disturbance (especially due to industrial activity like road building and logging) can lead to nest abandonment.

  • Predation on chicks by other raptors (e.g. great horned owl)

  • Reduction in prey base due to loss of habitat structure.

Key Conservation & Management Objectives

  • Maintain or enhance wild populations, well-distributed throughout their range, to a level that permits the removal of the at-risk status for A. g. laingi and prevents the attainment of at-risk status for A. g. atricapillus. (Cooper 2000).

ungulate winter ranges, old-growth management areas (OGMA's), inoperable areas and any other areas netted out of the timber harvesting land base or disturbance restricted.

  • Assess, inventory and monitor using methodology setout in the RISC standards # 11 Inventory Methods for Raptors (Version 2.0 http://ilmbwww.gov.bc.ca/risc/pubs/tebiodiv/raptors/version2/rapt_ml_v2.pdf

  • Apply methods as set out in Best Management Practices for Raptor Conservation during Urban and Rural Land Development in British Columbia. http://www.env.gov.bc.ca/wld/documents/bmp/raptor_bmp_final.pdf

  • Avoid activities that result in a reduction in stem density, canopy volume and habitat quality in forested stands (e.g. under storey brushing, patch cutting and clear-cutting)
  • Maintain the hierarchical structure of core zones and home range zones e.g. nest sites, nest areas, post-fledging area and foraging areas.

  • Core zones can be determined using nest sites (defined as a known nest tree and a 1 ha area surrounding it). Nest areas may contain several nest sites, and are approximately 12 ha, characterized by several stands of large, old trees with dense canopy cover. This area is at the centre of all breeding movements and behaviours, from courtship through fledging. Post-fledging areas (juvenile dispersal zones are approximately 240 ha. The "foraging area" occupies about 2400 ha including the post-fledging area.


  • Core zones should have limited access and no disturbance. The general wildlife measures (GWM's) for A. g. laingi (as an identified wildlife) specify a seral stage distribution that leaves 20% of the 2400 ha Wildlife Habitat Area (WHA) in old forest with an additional 40% in mature forest (or old forest if mature forest is not available).

  • Reduce harvesting of mature second growth stands that prevent mature forest structure from forming (e.g. harvesting at <100 years).

  • Use all available landscape level tools to maintain appropriate levels of non-fragmented habitat for this species (e.g. protected areas, riparian reserves and to some extent riparian management zones, any special management areas).
  • Maintain abundance of the habitat attributes critical for goshawk prey (snags, coarse woody debris, forest openings), and extensive canopy cover, which provides protection to fledglings while learning to hunt.

  • Sightings, specimens, or observations of activities threatening its habitat should be reported to the regional Species at Risk Biologist at the Ministry of Environment office




Main References/Literature Cited:

McLaren, Erica. 2004. “QUEEN CHARLOTTE” GOSHAWK” Accipiter gentilis laingi Accounts and Measures for Managing Identified Wildlife – Accounts V.

Cooper, J.M. and P.A. Chytyk. 2000. Update COSEWIC status report on the Northern Goshawk Laingi subspecies Accipiter gentilis laingi in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa.

Cooper, John M. and Victoria Stevens. February 2000. A Review of the Ecology, Management and Conservation of the Northern Goshawk in British Columbia.

International Forest Products Limited and Ministry of Water, Land and Air Protection. 2003. A Field Guide to Species at Risk in the Coast Forest Region of British Columbia: BC

Canadian Wildlife Service. 2010. Hinterlands Whose Who. Bird Fact Sheets: Sharp-shinned Hawk, Cooper's Hawk, and Northern Goshawk. Accessed July 2010.

Species & Ecosystems Explorer (BC Conservation Data Center Summary Report) http://www.env.gov.bc.ca/atrisk/toolintro.html

NatureServe Explorer - http://www.natureserve.org

Committee on the Status of Endangered Wildlife in Canada: http://www.cosewic.gc.ca/
Image credits:

Northern Goshawk & inset– USNPS/USDAFS

Habitat – Pamela Zevit


Draft June 2010



Disclaimer: This species account and related conservation recommendations are draft only and presently under review and subject to change.


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