Seasonal distribution of the Great Gray Owl (Strix nebulosa) in Southwestern Alberta

Abstract

Great Gray Owls (Strix nebulosa) have been banded and monitored west of Calgary in the foothills of Alberta from 1986 to 1996. Thirty-six adult owls have been banded: 16 males, 16 females and 4 of unknown sex. Great Gray Owls were captured during every month except August and October although the majority (56 percent) were banded from March-May (n=18). Four birds have been recaptured to date. A male was caught in the same location on 23 March and 9 May of 1986, a female was caught in the same location on 31 May 1987 and 18 November 1989, a female banded on 26 December 1988 was road-killed 14 km SSE on 19 September 1992, and a male banded on 17 June 1989 was recaptured 15 km NNE on 20 May 1990. Evidence of winter (non-breeding) territoriality has been observed. Seasonal change in abundance, indicative of a significant movement of birds into or out of the study area, has not been observed. Due to sub-regional variations in topography and climate, the study area encompasses a wide range of habitat types including muskeg, mature upland poplar-spruce mixed forest, old-growth riparian spruce forest and grasslands. The diversity inherent in this landscape appears to satisfy year-round habitat requirements for the Great Gray Owl, precluding a requirement for this species to exhibit large-scale seasonal migratory movements.

Parent Publication

• Biology and conservation of owls of the Northern Hemisphere: 2nd International symposium

Citation

Collister, Douglas M. 1997. Seasonal distribution of the Great Gray Owl (Strix nebulosa) in Southwestern Alberta. In: Duncan, James R.; Johnson, David H.; Nicholls, Thomas H., eds. Biology and conservation of owls of the Northern Hemisphere: 2nd International symposium. Gen. Tech. Rep. NC-190. St. Paul, MN: U.S. Dept. of Agriculture, Forest Service, North Central Forest Experiment Station. 119-122.