A practical guide to bird watching in Sonoma County, California
(Unless otherwise indicated, all phone numbers are in the 707 area code)
Canvasback is not a common duck in Sonoma County, but usually present in moderate numbers in the winter months in favored habitat, which includes fresh and saltwater marshes, estuaries, and inland ponds. Birds start arriving in the area in late October (although one or two are sometimes seen as early as mid-September). Most are gone by around the first week of April. Usually solitary, in pairs, or in small flocks when we see them, but large flocks have been noted in the county on occasion (see Parmeter and Wight) and commonly forms large flocks in many parts of its range. Large congregations noted for flying high and in neat V-formations. Often associates with Redheads (Aythya americana) where Redheads are common (not in Sonoma County). Rarely walks on land. Feeds mostly on roots of aquatic plants, but will also eat snails and small clams. Comparatively often seen at the Bodega Farm Pond. Also fairly regularly noted at the Las Gallinas Sewer Ponds, in neighboring Marin County as well as further south in the Bay Area.
Among the largest ducks we see in Sonoma County. Distinctive sloping forehead creates a profile unlike that of any other duck. Males have a rusty red neck and head (darker towards the base of the bill), black bill and red eye. Body is white in breeding plumage, with black at the breast and at the rump and tail. White areas become cream to dirty beige in winter plumage. Females caramel color at head, neck, and breast (darkest at breast), otherwise greyish to beige, but with black in the tail. Eye and bill black. Females are fairly easy to recognize just by size and silhouette, having the same sloping forehead as males. Similar to the closely related Redhead, but the Redhead is quite rare in the county. Redheads have a more uniformly red head and a much rounder head. The profile alone should distinguish Canvasback and Redhead, but note also that Redheads are grey where a Canvasback is more nearly white.
Trivia: 1. May be the victim of nest parasitism by Redheads.
Selected county sightings: Ellis Creek Water Recycling Plant (Feb 24, Colin Talcroft); Hudeman Slough (Feb 1, 2013, Colin Talcroft); Shollenberger Park (Feb 10, 2013, Ruth Rudesill); Bodega Fam Pond (Nov 22, 2012, Scott Carey); Chanslor Wetlands (Nov 11, 2012, Alan Wight); Bodega Farm Pond (Jan 11, 2012, Colin Talcroft); Bodega Farm Pond (Nov 17, 2011, Colin Talcroft); Shollenberger Park (Sep 17, 2012, Scott Carey); Shollenberger Park (Jun 24, 2011--a very late sighting, Ruth Rudesill); Ellis Creek Water Recycling Plant (Feb 20, 2010 (a flock of 119), Andy LaCasse)
Further reading:
Bolander and Parmeter, Birds of Sonoma County California, rev. ed., 2000, p. 32
Brinkley, National Wildlife Federation Field Guide to Birds of North America, 2007, p. 45
Dunn and Alderfer, eds., National Geographic Field Guide to the Birds of North America, 5th ed., 2006, p. 38
Dunn and Alderfer, eds., National Geographic Field Guide to the Birds of North America, 6th ed., 2011, pp. 34, 51
Dunne, Pete Dunne’s Essential Field Guide Companion, 2006, pp. 44-45
Ehrlich, Dobkin, and Wheye, The Birder's Handbook, paperback edition, 1988, p. 74
Fix and Bezener, Birds of Northern California, 2000, p. 86
Floyd, Smithsonian Field Guide to the Birds of North America, 2008, p. 44
Kaufman, Field Guide to Birds of North America, 2000, p. 34
Kaufman, Field Guide to Advanced Birding, 2011, pp. 90, 145, 157
Lukas, Bay Area Birds: From Sonoma County to Monterey Bay, 2012, pp. 16-17
Parmeter and Wight, Birds of Sonoma County California, Update (2000-2010), 2012, p. 7
Peterson, Birds of Eastern and Central North America, 5th ed., 2002, p. 76
Peterson, Field Guide to Birds of Western North America, 4th ed., 2010, p. 36, 48, 49
Peterson, Western Birds, 3rd ed., 1990, p. 56, 72, 73
Sibley, Field Guide to Birds of Western North America,1st ed., 2003, p. 84
Stokes, Stokes Field Guide to the Birds of North America, 1st ed., 2010, p. 33
Vuilleumier, American Museum of Natural History, Birds of North America: Western Region, 2011, p. 54
Voice: Cornell Lab of Ornithology: All About Birds--Canvasback
© 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.
Canvasback (male) Ellis Creek Water Recycling Plant, February 24, 2013
Canvasback
Aythya valisineria
1990-2013 Sonoma County data. Graph provided by eBird (www.ebird.org), generated May 30, 2013
EBird reported occurrence in Sonoma County
