A practical guide to bird watching in Sonoma County, California

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


Mew Gull is present in Sonoma County mostly during the winter months, but the earliest arrivals may show up as early as mid-September and birds have been sporadically reported in other months. Fairly common at the coast, usually through mid-April of the following year, but may also show up inland where it favors dumps, lakes, and flooded agricultural fields. The bird above was photographed well inland, at Lake Ralphine in Santa Rosa, which is not a regular hang-out for Mew Gull. Most commonly seen in the county at Bodega Bay, where it mixes casually with other gulls. Also fairly common in the winter at Ellis Creek Water Recycling Facility. Mew Gull attains full adult plumage in its third year. Breeds in Alaska and extreme northwestern Canada. Winters all along the West Coast of the US, and as far south as northern Baja California. Generally considered conspecific with Common Gull (Larus canus canus) and Kamtchatka Gull (Larus canus kamtschatschensis); our Mew Gulls are Larus canus brachyrynchus

Gulls can be terribly confusing, but Mew Gull is relatively easy to identify (the adults, anyway). The winter-plumage birds we see look like a somewhat smallish Ring-billed Gull (Larus delawarensis), but are distinguished by a number of features. Probably most obvious is the small, dull yellow, unmarked bill--without the dark ring that gives Ring-billed Gull its name (note, however, that Mew Gull in non-breeding plumage may show a hint of a dark ring, as in the bird pictured above). The bill is proportionately smaller than on any gull we regularly see. Also, note the lack of any bulge toward the tip of the bill. Mew Gull has a proportionately small, roundish head, unlike the larger, more elongated head of Ring-billed and other gulls. The eye is dark, whereas Ring-billed Gull has a pale iris (see photos below). The back is usually a somewhat darker grey than in Ring-billed Gull and winter birds tend to show more dark streaking on the head and neck, but head streaking is quite variable from bird to bird. Mew Gull has much more white in the primary tips, and that mark alone can distinguish the birds in flight (see photos below). Both birds have yellow legs (adults). Adults in breeding plumage lose the winter streaking on the head and neck, gain a red orbital ring, and the bill and gape brighten to a clear yellow. But, again, we almost always see winter-plumage Mew Gulls in Sonoma County. In my view, these are most easily distinguished from other gulls by the combination of small size; small, light bill; roundish head; dark eye; and the large white patches at the end of the wings in flight.

Juvenile Mew Gull (roughly July to September of the first year) is a pale, fairly uniformly scalloped greyish brown with an all-dark bill. First winter birds (October of the first year to April of the following year) will show grey on the back but with brownish coverts with weakly contrasting, paler edges; pale grey-brown underneath; pale grey-pink legs. By the first winter, the bill will be pink at the base, dark at the tip. Juvenile Ring-billed Gull will have more sharply contrasting dark wing projections. First winter Ring-billed Gull is much paler (mostly white) underneath. It will, like first-winter Mew Gull, have grey on the back, but the coverts will have much more strongly contrasting scalloping. See the usual guide books for detailed comparisons.

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

Selected county sightings: Lake Ralphine (December 3, 2011); Ellis Creek Water Recycling Facility (November 5, 2011); Goat Rock Beach (October 16, 2011, Lisa Hug); Bodega Bay (February 5, 2011). Lake Ralphine (January 10, 2011, Doug Shaw).

Further reading:

Bolander and Parmeter, Birds of Sonoma County California, rev. ed., 2000, p. 61

Brinkley, National Wildlife Federation Field Guide to Birds of North America, 2007, p. 126

Dunn and Alderfer, eds., National Geographic Field Guide to the Birds of North America, 5th ed., 2006, pg. 202

Dunn and Alderfer, eds., National Geographic Field Guide to the Birds of North America, 6th ed., 2011, pg. 220

Howell and Dunn, Gulls of the Americas, 2007, pp. 126, 127-132, 375, 377-380

Dunne, Pete Dunne’s Essential Field Guide Companion, 2006, p. 260-261

Ehrlich, Dobkin, and Wheye, The Birder's Handbook, paperback edition, 1988, pg. 172

Fix and Bezener, Birds of Northern California, 2000, p. 173

Floyd, Smithsonian Field Guide to the Birds of North America, 2008, p. 185

Kaufman, Field Guide to Birds of North America, 2000, p. 78

Kaufman, Advanced Birding, 1990, pp. 102-108 (general notes on gull ID), pp. 89, 117, 125

Kaufman, Field Guide to Advanced Birding, 2011, pp. 242-263 (general notes on gull ID), pp. 257, 258, 260, 302

Lukas, Bay Area Birds: From Sonoma County to Monterey Bay, 2012, pp. 122-123

Parmeter and Wight, Birds of Sonoma County California, Update (2000-2010), 2012, p. 35

Peterson, Birds of Eastern and Central North America, 5th ed., 2002, p. 178

Peterson, Field Guide to Birds of Western North America, 4th ed., 2010, p. 174

Peterson, Western Birds, 3rd ed., 1990,  p. 92

Sibley, Field Guide to Birds of Western North America,1st ed., 2003, p. 186

Stokes, Stokes Field Guide to the Birds of North America, 1st ed., 2010, pp. 310-311

Vuilleumier, American Museum of Natural History, Birds of North America: Western Region, 2011, p. 165

Voice: Cornell Lab of Ornithology: All About Birds--Mew 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.


Mew Gull, Lake Ralphine, Santa Rosa, December 3, 2011

Mew Gull (winter plumage): Note small, dull yellow bill lacking ring; small head, dark eye

For comparison: Ring-billed Gull (winter plumage): Note ring on bill; somewhat elongated head, pale iris

For comparison: Adult Ring-billed Gull, winter plumage: The bill ring is often visible in flight. Note the distinct black wing tips with very small white spots--note also how deceptive shadows can be

Mew Gull (winter plumage): Note Large white patches on the two outermost primaries (p10 and p9)

and the very distinct white fringe on trailing edge of wing

For comparison: Adult Ring-billed Gull, winter plumage: A view of the wingtip coloration--mostly black with one medium-size spot on p10, no spot at all on p9, other white spots very small

First-cycle Mew Gull

Lake Ralphine, December 22, 2011

Mew Gull

Larus canus

1990-2013 Sonoma County data. Graph provided by eBird (www.ebird.org), generated July 27, 2013

EBird reported occurrence in Sonoma County