||Movements of the Northern Goshawk (Accipiter gentiles atricapillus) in a fragmented forest landscape: preliminary results from the East Kootenay Northern Goshawk Research Program - 2004/2005 annual report|
|Contributing Authors: Harrower, William L.; Stuart-Smith, Kari; Larsen, Karl W.|
|Imprint: Victoria, B.C. : University of Victoria, 2005|
|Subject: Forest Investment Account (FIA), Northern goshawk, British Columbia|
|Series: Forest Investment Account (FIA) - Forest Science Program|
|In south-eastern British Columbia, the northern goshawk (Accipiter gentiles atricapillus) is under consideration as one of a suite of focal species that will be used to guide forest management. Despite the interest in this animal, specific information on its critical resource requirements is lacking. This project was designed to fill this knowledge gap. Specifically, we are: (1) determining the survival of goshawks during the post-fledgling period; (2) documenting how current forest practices around goshawk nest areas influence the post-fledging movements of fledgling birds; (3) examining how the movements of adult goshawks, during the breeding and rearing season, influence the movements of fledgling birds within the post-fledging area; and (4) documenting the extent of adult goshawk winter movements and nest area fidelity. During the spring of 2004, we captured and radio-tagged 27 goshawks (15 juvenile and 12 adults) at 10 nest sites in the East Kootenay region of south-eastern British Columbia. Due to the mortality of 4 juvenile goshawks, we were successful documenting the breeding and rearing season movements of adult and fledgling goshawks at 6 nest sites. Fledgling goshawks remained close to the nest. During the first 25 days of the post-fledging period fledglings, 98% of locations were within 300 m of the nest. After 25 days post-fledging, 96% of locations obtained within 500m of the nest site. The average home range of fledglings was estimated to be 20.2ha (±17.5 SD, n=11). Adult female goshawks range on average 991 m (±423 SD, n=96) from the nest during this period and we estimated their home range size to be 3036.6 ha (±2577.9 SD, n=6). In contrast, adult males remained closer to nest sites, with an average home range of 1707.0 ha (±713.7 SD, n=2). Winter movements suggest that the majority of adult female goshawks from the East Kootenays remain within our study area during the winter months and move on average only 6.4 km (±6.0 SD, n=34) from their previous years nest area. Both adult males moved out of the study area. These preliminary results will help us to develop effective hypotheses regarding the factors influencing the movements of goshawks within the East Kootenay region and allow us to guide future investigations. This information will be used to develop effective management plans for this species.|
prepared by: William Harrower, Kari Stuart-Smith, and Karl Larsen.