Introduction

Editor's Note: Based on recent mitochondrial DNA sequence data, as well as on earlier behavioral and distributional data, the 47th Supplement to the American Ornithologists' Union's Checklist of North American Birds has recognized the two groups of Blue Grouse (Dusky and Sooty) as separate species. Future revisions of this account will reflect this change. See Systematics for a history of the taxonomy and nomenclature of this species—and findings that have generated this split.

Blue Grouse are endemic to mountainous regions of western North America and have a restricted geographic range (Fig. 1). Nevertheless, this species occupies a wide range of breeding habitats from maritime to continental in climate, from sea level to 3,600+ m in elevation, and from northwestern coast rain forest to shrub/steppe high desert and subalpine/alpine tundra. Virtually all populations winter in conifer forest, where conifer needles comprise the main winter food. Their distribution appears to be partly determined by the proximity of suitable breeding areas to montane forest acceptable for use in winter. As a species, Blue Grouse share physical and behavioral attributes with both ‘forest’ and ‘prairie’ grouse in the subfamily Tetraoninae.

Blue Grouse can attain high population densities and remain distributed throughout most of their historic range. Occupation of relatively inaccessible montane forests during much of the year contributes to a generally healthy status in many areas.

Biologists currently recognize 8 subspecies of Blue Grouse, which separate into two main groups:  Sooty Grouse and Dusky Grouse, corresponding to the western and eastern (or interior) subspecies groups, respectively. Once considered separate species, these groups deserve further study; increasing evidence - including mitochondrial DNA - suggests these groups are distinct lineages and may be separate species.