Migration in a Local Population of Spruce Grouse

Migration of Spruce Grouse was observed in southwestern Alberta from 1970 to 1975 in a population of grouse that included both migratory and resident birds. Migrants comprised 39% of this population; these individuals migrated each year regardless of weather conditions. Migration occurred from mid-February to late May and from early September to mid-December. More females than males were migratory and females migrated longer distances. Distance between breeding and wintering sites ranged from 0.5 to 9.5 km. Survival and reproductive success was similar for migrant and resident grouse during the study. Migration was generally related to the dispersal history of birds as yearlings. Yearlings that dispersed in spring tended to establish migratory patterns by returning to winter sites used as juveniles. Why these birds did not remain on summer areas for the winter, as did resident Spruce Grouse, is uncertain. The quality of winter habitat may be an important factor in establishment of migration; further investigation is required to determine the qualitative aspects of the breeding and wintering habitat of Spruce Grouse.