Habitat Selection by Sympatric Spruce and Ruffed Grouse in North Central Minnesota

Abstract

Fifteen spruce grouse (Canachites canadensis) and 7 ruffed grouse (Bonasa umbellus) were radio-tracked between December 1977 and June 1979 in a 10-km2 area in Minnesota. Additional data were collected from display site and nest surveys and from direct observations. In months of snow cover, all spruce grouse preferred jack pine (Pinus banksiana) upland; from May through September all males and most females selected coniferous lowlands. Strong preferences for display sites in black spruce (Picea mariana) bogs and for nest sites in mixed bogs suggest that such lowlands may be critical for reproduction. Ruffed grouse varied considerably in patterns of habitat use. Logs used for drumming, nests, and broods were most frequently in alder (Alnus spp.) or upland-alder edge, suggesting that alder habitat may be important to the success of these ruffed grouse. Spruce grouse and ruffed grouse overlapped little in habitat use during snow-free periods. During periods of snow cover they both showed increased use of upland conifers. We believe the interspersion of lowland habitats with jack pine uplands allows ruffed and spruce grouse to coexist. J. WILDL. MANAGE. 46(2):391-403 Spruce and ruffed grouse occur sym- patrically throughout portions of their range in North America with the latter being considered a species dependent upon subclimax deciduous forests and the former upon climax coniferous for- ests. In Minnesota, habitat selection by spruce grouse has been studied by An- derson (1973) and Haas (1974) while Eng (1959), Kupa (1966), Godfrey (1975), and Maxson (1978) investigated habitat use by ruffed grouse. Few of these studies were conducted in areas that contained a wide variety of both upland and low- land habitats and none was conducted in an area that contained both species of grouse. Only Robinson (1969) in Michi- gan attempted to evaluate habitat use by both grouse on the same site at the same time. However, his research focused pri-