Skagit River Bald Eagles: Movements, Origins and Breeding Population Status
	August 1998 Progress Report - [PDF Format 891K] In the winter of 1997-98 we completed the second season of an investigation into the origins and breeding population status of bald eagles (Haliaeetus leucocephalus) on the Skagit River, Washington. We captured 14 adult eagles and 5 subadult eagles, for a total of 23 adults and 37 eagles captured during the study. As of July, 1998, 17 of the 23 satellite transmitters (PTTS) deployed on adult eagles were transmitting, and 4,760 satellite locations had been received. Satellite monitoring of adult eagles during spring migration (16 February to 5 April, n = 25 movements), and fall migration (8 August and 14 December, n = 5 movements) found eagles migrated along the coastal corridor from Washington to southeast Alaska, and through interior British Columbia along the Fraser River. Of 20 telemetered eagles, 40% originated from British Columbia, 35% from Alaska, 20% from the Northwest Territories, and 5% from the Yukon Territory. Breeding adults comprised 50% of the 16 adults for which nesting status was determined. Four of 5 eagles captured in winter 1996-97 returned to the Skagit River for nearly 3 weeks (average = 20 ± 23 days) of the 8 weeks (average = 55 ± 28 days) they spent in Washington and southwestern British Columbia in winter 1997-98. With the exception of 1 eagle that moved to the Feather River in northern California, winter movements of the 23 eagles in Washington were confined to the area east from the San Juan Islands to the Columbia River. In winter 1998-99, we plan to complete deployment of PTTS, and conduct further behavioral observations of telemetered eagles to assess daily movements and activity patterns.
	August 1997 Progress Report - [PDF Format 702K] In the winter of 1996-97, a study was initiated to investigate the origins and breeding population status of bald eagles (Haliaeetus leucocephalus) wintering on the Skagit River, Washington. Eighteen eagles were trapped on river bars, including 9 adults that were affixed with satellite transmitters. Following capture, eagles spent from 1 to 52 days on the river. Northward migration was along coastal British Columbia, and through interior British Columbia. Most eagles arrived at breeding areas in April. Eagles originated from widely dispersed populations from southern British Columbia to northern Yukon territory, and east along the McKenzie River in Northwest Territories. As of mid-June, two adults had been observed on breeding areas. Satellite monitoring will continue into fall, 1997, with plans to deploy at least 6 additional transmitters in winter 1997-98.

If you would like a reprint of any of the reports listed below please send an
email request to wildthing@dfw.wa.gov. Please note some reports may be out of print.

Garrett, M.G., J.W. Watson, and R. G. Anthony. 1993. Bald eagle home range and habitat use in the Columbia River estuary. Journal of Wildlife Management 57:19-27.

Garrett, M.G., R.G. Anthony, J.W. Watson, and K. McGarigal. 1988. Ecology of bald eagles on the Lower Columbia River. Army Corps of Engineers, Portland District. Portland, Oregon, USA.

Watson, J.W. 1990. Bald eagle dies from entanglement in fish net. Journal of Raptor Research 23:52-53.

Watson, J.W. 1992. Status and distribution of bald eagles in Washington. Northwest Science 66:126.

Watson, J.W. 1993. Responses of nesting bald eagles to helicopter surveys. Wildlife Society Bulletin 21:171-178.

Watson, J.W., and B.C. Cunningham. 1996. Another occurrence of bald eagles rearing a red-tailed hawk. Washington Birds 5:51-52.

Watson, J.W., and D. John Pierce. 1997. Movements and Ranges of nesting bald eagles at Naval Air Station Whidbey Island as determined by satellite telemetry. Final Report. Washington Department of Fish and Wildlife, Olympia, Washington, USA.

Watson, J.W., and D. John Pierce. 1998. Migration, diets, and home ranges of breeding bald eagles along Hood Canal and at Indian Island, Washington. Final Report. Washington Department of Fish and Wildlife, Olympia, Washington, USA.

Watson, J.W., and D. John Pierce. 1998. Bald eagle ecology in western Washington with an emphasis on the effects of human activity. Final Report. Washington Department of Fish and Wildlife, Olympia, Washington, USA.

Watson, J.W., D. Mundy, J. S. Begley, and D.J. Pierce. 1995. Responses of nesting bald eagles to the harvest of geoduck clams (Panopea abrupta). Final Report. Washington Department of Fish and Wildlife, Olympia, Washington, USA.

Watson, J.W., and KR. McAllister. 1993. Breeding distribution, population trends, and management of five diurnal raptor species in Washington state. Journal of Raptor Research 27:94.

Watson, J.W., M. Davison, and L.L. Leschner. 1993. Bald eagles rear red-tailed hawks. Journal of Raptor Research 27:126-127.

Watson, J.W., and R.G. Anthony. 1986. Ecology of bald eagles in the Tongue Point Area, Lower Columbia River. Army Corps of Engineers, Portland District. Portland, Oregon, USA.

Watson, J.W., R. G. Anthony, and M.G. Garrett. 1991. Time budgets and foraging ecology of bald eagles in the Columbia River estuary. Journal of Wildlife Management 55:492-499.

Files formatted in Adobe Portable Document Format (PDF) require the Adobe Acrobat Reader to view and print. You can download the free reader directly from Adobe. Windows versions are approximately 4MB in size.