A practical guide to bird watching in Sonoma County, California

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


Glaucous-winged Gull is present in Sonoma County mostly in the winter months, although a few birds may stay over the summer, notably at Bodega Bay. The birds usually start arriving in mid-October, but the bulk of the incoming population seems to arrive in early November. Birds usually stay through mid-March, but a few may linger into April. Generally present only sporadically between May and September. Breeds in coastal southern Alaska and coastal British Columbia, moving south during the winter months into our area and as far south as northern Baja California. Glaucous-winged Gull attains adult plumage in its fourth year.

The adults we see are large, pink-legged gulls with a medium to pale grey mantle (often with a bluish hint in non-breeding plumage) and primaries about the same color as the mantle. The white spots visible in the folded wings of standing Glaucous-winged Gulls (as in the photo above) are distinct but contrast less sharply with the primaries than do the same spots in nearly all the other gulls we commonly see in the county. All locally present adult gulls have black or near-black primaries--with the exception of the rather rare Glaucous Gull (Larus hyperboreus), which has virtually white primaries. Glaucous-winged gull has a fairly heavy yellow bill marked with a red spot on the lower mandible. The head, neck, and upper breast are smudged with grey rather than streaked as in many other winter gulls in non-breeding plumage. Note that the folded wings project only slightly beyond the end of the white tail. Eye-color seems to be quite variable in this gull. The bird photographed above has a fairly pale eye and some field guides illustrate Glaucous-winged Gull with a pale iris (Birds of Northern California, for example), but most descriptions call the eye dark. Known to frequently hybridize with Western Gull and these birds backcross with their parent species, which creates a wide range of intermediate birds that can be very confusing indeed. 

Also see: A comparison of common gull heads in breeding and non-breeding plumages   

Selected county sightings: Goat Rock Beach, Jenner (February 23, 2012); Roberts Park (December 12, 2011); Lucchesi Park, (November 14, 2011, Gene Hunn); Duncan's Landing (March 10, 2011); Duncan's Landing (February 26, 2011, Bill Doyle); Bodega Bay (April 1, 2010)

Further reading:

Bolander and Parmeter, Birds of Sonoma County California, rev. ed., 2000, p. 63

Brinkley, National Wildlife Federation Field Guide to Birds of North America, 2007, p. 128

Dunn and Alderfer, eds., National Geographic Field Guide to the Birds of North America, 5th ed., 2006, pg. 210

Dunn and Alderfer, eds., National Geographic Field Guide to the Birds of North America, 6th ed., 2011, pg. 228

Dunne, Pete Dunne’s Essential Field Guide Companion, 2006, pp. 268-269

Fix and Bezener, Birds of Northern California, 2000, p. 179

Floyd, Smithsonian Field Guide to the Birds of North America, 2008, p. 189

Howell and Dunn, Gulls of the Americas, 2007, pp. 14, 15, 22, 27, 29, 158, 176,  235-243, 264, 274, 276, 393, 453-457

Ehrlich, Dobkin, and Wheye, The Birder's Handbook, paperback edition, 1988, pg. 176

Kaufman, Field Guide to Birds of North America, 2000, p. 82

Kaufman, Advanced Birding, 1990, pp. 102-108 (general notes on gull ID), pp. 114-129

Kaufman, Field Guide to Advanced Birding, 2011, 242-263 (general notes on gull ID), pp. 12, 123, 251, 259, 265, 266, 267

Lukas, Bay Area Birds: From Sonoma County to Monterey Bay, 2012, pp. 128, 129-130

Parmeter and Wight, Birds of Sonoma County California, Update (2000-2010), 2012, pp. 36

Peterson, Field Guide to Birds of Western North America, 4th ed., 2010, pp. 176, 184

Peterson, Western Birds, 3rd ed., 1990,  p. 94

Sibley, Field Guide to Birds of Western North America,1st ed., 2003, p. 193

Stokes, Stokes Field Guide to the Birds of North America, 1st ed., 2010, pp. 330-331

Vuilleumier, American Museum of Natural History, Birds of North America: Western Region, 2011, p. 168

Voice: Cornell Lab of Ornithology: All About Birds--Glaucous-winged Gull



© 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.


Glaucous-winged Gull, winter plumage. Roberts Park, Rohnert Park, December 12, 2011

Glaucous-winged Gull (foreground, Western Gull behind), winter plumage. Goat Rock Beach, February 21, 2012

Note the paler, somewhat bluish mantle relative to the Western Gull. Note also the grey rather than black primaries, and the wash of color on the head (Western Gull always has a clear white head, even in winter or non-breeding plumage).

Glaucous-winged Gull

Larus glaucescens

1990-2013 Sonoma County data. Graph provided by eBird (www.ebird.org), generated July 5, 2013

EBird reported occurrence in Sonoma County