A practical guide to bird watching in Sonoma County, California
(Unless otherwise indicated, all phone numbers are in the 707 area code)
Common in much of Sonoma County and present year-round. The most common predatory bird in North America. Our largest owl and probably the most commonly noted owl even if only heard. Mostly nocturnal but often active during the day. Usually perches high in large trees, if not on wires or fences. Often found in forest edge habitats but seen in parks, orchards, farmland, and suburbia. The bird photographed above was in my own back yard. Hunts for mostly mammalian prey, large and small--even happy to take skunks--but also feeds on large insects, birds, and amphibians when available. Nests in much of the county. When roosting, may be mobbed by jays and crows. The bird above attracted nearly 100 crows for several hours.
Easily identified by its large size (averaging about 22 inches in height); apparent lack of a neck; barrel-chested silhouette; large, wide-set yellow eyes set in an orange-ish, darkly-outlined facial disc; and large, widely spaced “ear” tufts (the bird’s real ears are actually lower on its head). Coloration varies geographically, but typically heavily mottled grey, brown and black above, finely barred horizontally with dark brown over buff below. Buffy under the wings. White at the chin is conspicuous particularly at dusk and dawn. Gives the overall impression of being a warm, medium brown.
Superficially similar to Long-eared Owl (Asio otus), but that bird is smaller, notably slimmer, and much rarer in Sonoma County than Great Horned Owl. The facial patterns differ markedly (see comparison photo below).
Further reading:
Bolander and Parmeter, Birds of Sonoma County California, rev. ed., 2000, p. 71
Brinkley, National Wildlife Federation Field Guide to Birds of North America, 2007, p. 258
Burridge, ed., Sonoma County Breeding Bird Atlas, 1995, p. 79
Dunn and Alderfer, eds., National Geographic Field Guide to the Birds of North America, 5th ed., 2006, p. 256
Dunn and Alderfer, eds., National Geographic Field Guide to the Birds of North America, 6th ed., 2011, p. 282
Dunne, Pete Dunne’s Essential Field Guide Companion, 2006, p. 330
Ehrlich, Dobkin, and Wheye, The Birder's Handbook, paperback edition, 1988, p. 292
Fix and Bezener, Birds of Northern California, 2000, p. 206
Floyd, Smithsonian Field Guide to the Birds of North America, 2008, p. 239
Kaufman, Field Guide to Birds of North America, 2000, p. 130
Kaufman, Field Guide to Advanced Birding, 2011, brief mention p. 317
Lukas, Bay Area Birds: From Sonoma County to Monterey Bay, 2012, pp. 151-152
Parmeter and Wight, Birds of Sonoma County California, Update (2000-2010), 2012, p. 42
Peterson, Birds of Eastern and Central North America, 5th ed., 2002, p. 202
Peterson, Field Guide to Birds of Western North America, 4th ed., 2010, p. 214
Peterson, Western Birds, 3rd ed., 1990, p. 200
Sibley, Field Guide to Birds of Western North America,1st ed., 2003, p. 239
Stokes, Stokes Field Guide to the Birds of North America, 1st ed., 2010, p. 399
Vuilleumier, American Museum of Natural History, Birds of North America: Western Region, 2011, p. 204
Voice: Cornell Lab of Ornithology: All About Birds--Great Horned Owl
© Colin Talcroft, 2009-2016
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.
Great Horned Owl, Stone Castle Lane, Santa Rosa, January 16, 2016
Great Horned Owl
Bubo virginianus
1995-2016 Sonoma County data. Graph provided by eBird (www.ebird.org), generated January 18, 2016
Reported occurrence in Sonoma County
For comparison: Long-eared Owl
Las Gallinas Sewer Ponds, San Rafael, January 7, 2013