NORTHERN GOSHAWK (Accipiter gentilis atricapillus - Accipiter gentilis laingi)
Two subspecies of the northern goshawk occur in British Columbia: A. g. atricapillus and A. g. laingi. Hereafter referred to as the Queen Charlotte goshawk, A. g. laingi is RED-listed because the population is sparse, restricted to coastal forest, and heavily reliant on mature-to-old forest. It is designated as VULNERABLE in Canada by COSEWIC. A. g. atricapillus is considered to be REGIONALLY IMPORTANT. It is considered a species of conservation concern because it is associated with habitats that are becoming rare, and it is a species for which B.C. has a global responsibility because adjacent jurisdictions have listed it at risk. This subspecies is designated as NOT AT RISK in Canada by COSEWIC.
The species is a robust, long-tailed and short-winged accipiter. It generally feeds on large prey, including birds such as crows, varied thrush, grouse, woodpeckers, sapsuckers, Steller's jays and mammals such as hares, squirrels, ground squirrels and chipmunks. Major prey are usually associated with old-growth forests or forest edges.
The breeding and brood-rearing season extends from April to September. Clutches of 3-4 eggs are incubated for 30-32 days, and chicks fledge at approximately 35-42 days of age. After fledging, chicks remain in the vicinity of the nest for 30-50 days.
The home range is hierarchically organized, composed of nest sites, nest areas, a post-fledging area and a foraging area. The "nest site" is defined as a known nest tree and a 1 ha area surrounding it. The "nest area," which may contain several nest sites, is approximately 12 ha, and is 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. The "post-fledging area" (approximately 240 ha) surrounds the active nest area and 1-2 alternate nest areas, and corresponds roughly to the defended area of the breeding pair. It is characterized by an 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. The "foraging area" occupies about 2400 ha including the post-fledging area. It may include a diversity of landforms and forest cover types, but areas with greater canopy cover, greater basal area, and more trees per hectare are used more frequently in some parts of the species range. In Alaska, the Queen Charlotte goshawk prefers high productivity old forest, and avoids early seral forests.
Most of the global range of the Queen Charlotte goshawk is in B.C. It occurs in three disjunct populations along the Pacific Coast, from southeast Alaska to western Washington. The first of these occupies the Alexander Archipelago and a narrow mainland strip below the Coast Mountains, in southeast Alaska. The second occurs on the Queen Charlotte Islands, about 250 km to the southwest. The third population occurs on Vancouver Island.
The Queen Charlotte goshawk may also occur along the coastal mainland of B.C., particularly opposite the Alaskan populations in the Stikine River area, but records to date provide evidence only for the presence of A. g. atricapillus on the mainland.
The northern goshawk (atricapillus) breeds throughout the province, with the exception of Vancouver Island and the Queen Charlotte Islands, where the laingi subspecies is found.
The northern goshawk is considered to occur in all mainland ecosections.
CAM: QCL, SKP, WQC, NWL, NIM, WIM, (HEL, OUF, BOR - possible)
GED: LIM, NAL (GEL - possible)
All except Alpine Tundra (AT)
CDF: CDFmm
CWH: CWHwh, CWHvh, CWHxm, CWHdm, CWHmm, CWHvm
MH: MHwh Mhmm
AC, BA, BB, BG, BL, BP, CB, CD, CS, CP, CW, DA, DF, DL, DP, EF, EW, FR, HB, HL, HS, IG, IH, IS, LP, MF, PP, PR, RB, RD, RR, SD, SF, SK, SL, SR, SW, WB, WR, YB, YM, YS
CB, CD, CG, CH, CP, CR, CW, DA, EF, FR, HB, HL, HS, LP, RS, SR, WB, YB
6: mature forest
7: old forest
The nest area is situated in stands of large trees, with dense canopies and relatively open understories. Nesting habitat is typically on gentle slopes, usually less than 30% slope, and always less than 60% slope.
The post-fledging area contains numerous feeding perches (stumps, downed snags, large horizontal limbs below the canopy), and their relatively open understorey is thought to facilitate the pursuit and capture of prey. The post-fledging area should provide abundant hunting opportunities to young, while maintaining higher than average cover from predators.
The post-fledging area is characterized by a mosaic of structural stages, and coarse woody debris throughout, which provides extensive and varied habitat for the prey base of the goshawk. Telemetry studies have shown that the northern goshawk avoids foraging in open habitats, selecting sites with more and larger trees, and increased canopy closure. Approximately 70% of Queen Charlotte goshawk activity occurs in high productivity old orest within the home range.
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