. "Forty-seventh Supplement to the American Ornithologists' Union Check-list of North American Birds"@en. . . . . "Source: Freebase - The World's database". . . . . . . . . . . "2006". . . . . . . . . . . "Blue Grouse split into Sooty and Dusky Grouse on the basis of evidence from mitochondrial DNA sequence data that supports the previous separation based on behavior, plumage, and vocalizations"@en. . . . . "Blue Grouse split into Sooty and Dusky Grouse on the basis of evidence from mitochondrial DNA sequence data that supports the previous separation based on behavior, plumage, and vocalizations"@en. . . "926-936". "3". "123". . . .