A practical guide to bird watching in Sonoma County, California

(Unless otherwise indicated, all phone numbers are in the 707 area code)


Sooty Grouse (today Dendragapus fulginosus) and Dusky Grouse (today Dendrapagus obscurus) were long considered a single species, Blue Grouse, which had the latin species name obscuras. Some researchers in the early 20th century considered the two birds distinct (the Wikipedia article on Sooty Grouse mentions research by Brooks, 1929 based on "morphology, behavior, and vocalizations"), but by the early 1940s, the consensus appears to have been that Sooty Grouse was the darker, coastal subspecies of Blue Grouse. In 2006, however, the American Ornithologist's Union split them again based on recent DNA research, giving obscuras to Dusky Grouse, fulginosus to Sooty Grouse.

Present year-round, but not that common and distribution limited to the heavily wooded northwestern part of the county. Favors forested areas but frequently forages at forest edges, meadow edges, and edges of other large clearings. Often moves to higher elevations (sometimes near the timberline) in late summer while spending the winter months at lower elevations. Roosts in coniferous trees, but forages on the ground. Comparatively tame when approached.

Sooty Grouse is a large, dark, brownish-grey grouse with a relatively long tail as grouses go. Females are browner and more speckled than males, which have a dark tail with a pale grey terminal band and a yellow band above the eye. Females usually plainer and greyer below. In display, the male exposes yellowish air sacs at the "shoulder" surrounded by white feathers and shows yellow-orange eye combs (in Dusky Grouse, the air sacs are a purplish red). Courting males give a series of five or six loud hoots in the early spring (usually from a perch in a tree) to attract females. These may be heard at very great distances. Guide books note that females may be confused with female Ruffed Grouse (Bonasa umbellus), but the latter does not usually occur in Sonoma County. Female Ruffed Grouse has a more crested look and a dark band at the tip of the tail lacking in Sooty Grouse.

Further reading:

Bolander and Parmeter, Birds of Sonoma County California, rev. ed., 2000, p. 44 (as Blue Grouse)

Brinkley, National Wildlife Federation Field Guide to Birds of North America, 2007, p. 172 (as Dusky/Sooty Grouse)

Burridge, ed., Sonoma County Breeding Bird Atlas, 1995, p. 56 (as Blue Grouse)

Dunn and Alderfer, eds., National Geographic Field Guide to the Birds of North America, 5th ed., 2006, p. 60

Dunn and Alderfer, eds., National Geographic Field Guide to the Birds of North America, 6th ed., 2011, p. 62

Ehrlich, Dobkin, and Wheye, The Birder's Handbook, paperback edition, 1988, p. 250 (as Blue Grouse)

Fix and Bezener, Birds of Northern California, 2000, p. 124

Kaufman, Field Guide to Birds of North America, 2000, p. 138 (as Blue Grouse)

Parmeter and Wight, Birds of Sonoma County California, Update (2000-2010), 2012, p. 11

Peterson, Field Guide to Birds of Western North America, 4th ed., 2010, p. 56

Peterson, Western Birds, 3rd ed., 1990,  p. 164 (as Blue Grouse)

Sibley, Field Guide to Birds of Western North America,1st ed., 2003, p. 127 (as Blue Grouse)

Stokes, Stokes Field Guide to the Birds of North America, 1st ed., 2010, p. 64

Vuilleumier, American Museum of Natural History, Birds of North America: Western Region, 2011, p. 30

Voice: Cornell Lab of Ornithology: All About Birds--Sooty Grouse



© Colin Talcroft, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016

Unless noted, all photos by the author. If you would like to use one of my images, please ask for permission for non-commercial use with proper credit or commercial use with proper compensation.


Sooty Grouse, Lassen County, August 12, 2012

Sooty Grouse

Dendragapus fulginosus

1995-2015 Sonoma County data. Graph provided by eBird (www.ebird.org), generated December 24, 2015

EBird-reported occurrence in Sonoma County