A practical guide to bird watching in Sonoma County, California

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

Common in oak and mixed woodlands throughout Sonoma County. Likely to be found anywhere there are mature oaks--which is most of the county except right at the coast and the southern marshy areas bordering San Pablo Bay. Breeds virtually everywhere it’s present in the county. Forms social groups of closely related individuals. Nests communally, using oaks and other trees. Highly social at all times. Loud, active, and hard to miss when present. Dependent on acorns as its main food source, but Acorn Woodpeckers will eat insects (the latin species name means “ant eater”) and in the summer months drink tree sap, when available. Stores acorns in holes excavated in “granary trees,” which may be trees of any kind or even utility poles (photo at left). There is a large granary pole at Spring Lake, for example. The large oak in front of Paradise Ridge Winery is a communal nesting site. Voice sounds like a cynical, gravelly laugh. Once heard, never forgotten. 

From the neck down, the Acorn Woodpecker is fairly sedately patterned, all in black and white, but garishly decorated from the neck up, its face often described as clown-like. Males (pictured above) have an all-red crown, white forehead and yellowish throat. Black around the eye and at the base of the black bill. Pale iris, usually whitish, but sometimes tending toward amber. Black at the upper breast with streaking from there down the belly, with streaking heaviest near the upper breast. Finely spotted at the vent. Upper parts mostly black. Upper back is actually tinged a deep Prussian blue, but the bird generally looks simply black, except in strong light. Tail black but notice the prominent white rump patch.The rump patch and white patches in the otherwise black wings are conspicuous features in flight. Typical undulating woodpecker flight pattern. Females very much the same but red on head is restricted to the back half of the crown.

Further reading:

Bolander and Parmeter, Birds of Sonoma County California, rev. ed., 2000, p. 78

Brinkley, National Wildlife Federation Field Guide to Birds of North America, 2007, p. 274

Burridge, ed., Sonoma County Breeding Bird Atlas, 1995, p. 91

Dunn and Alderfer, eds., National Geographic Field Guide to the Birds of North America, 5th ed., 2006, p. 282

Dunn and Alderfer, eds., National Geographic Field Guide to the Birds of North America, 6th ed., 2011, p. 312

Dunne, Pete Dunne’s Essential Field Guide Companion, 2006, pp. 373-374

Ehrlich, Dobkin, and Wheye, The Birder's Handbook, paperback edition, 1988, p. 344

Fix and Bezener, Birds of Northern California, 2000, p. 228

Floyd, Smithsonian Field Guide to the Birds of North America, 2008, p. 276

Kaufman, Field Guide to Birds of North America, 2000, p. 210

Lukas, Bay Area Birds: From Sonoma County to Monterey Bay, 2012, pp. 166-168

Parmeter and Wight, Birds of Sonoma County California, Update (2000-2010), 2012, p. 46

Peterson, Field Guide to Birds of Western North America, 4th ed., 2010, p. 236

Peterson, Western Birds, 3rd ed., 1990,  p. 222

Sibley, Field Guide to Birds of Western North America,1st ed., 2003, p. 267

Stokes, Stokes Field Guide to the Birds of North America, 1st ed., 2010, p. 438

Vuilleumier, American Museum of Natural History, Birds of North America: Western Region, 2011, p. 230

Voice: Cornell Lab of Ornithology: All About Birds--Acorn Woodpecker




© Colin Talcroft, 2009, 2010, 2011, 2012, 2013

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.


Acorn Woodpecker (male), Howarth Park, Santa Rosa, January 15, 2013

Acorn Woodpecker

Melanerpes formicivorus

1990-2013 Sonoma County data. Graph provided by eBird (www.ebird.org), generated May 30, 2013

EBird reported occurrence in Sonoma County