A practical guide to bird watching in Sonoma County, California
(Unless otherwise indicated, all phone numbers are in the 707 area code)
Sometimes it's hard to believe such a small bird can make such a racket. In the spring, dozens may be singing noisily without pause within a lazy stone's throw of one another in marshy areas with dense stands of reeds, grasses, cattails, and the like. Uses both freshwater and brackish marshes. Much easier to hear than see. Secretive and very well camouflaged. Often sings hidden at the base of reeds, but will sing out in the open on breeding territory. Builds multiple dummy nests (sometimes as many as 20) and uses some of these during non-breeding season to roost in. One male typically mates with multiple females. Known to destroy eggs of other marsh wrens and eggs of blackbirds nesting in marshes. Blackbirds apparently reciprocate.
Usually identified by its buzzy, liquid singing in dense stands of reeds or other tall aquatic plants rather than by sight, but Marsh Wren is a typical wren--a small brown bird with a short, striped tail (often held cocked), and a long, sharp bill. Compared with other wrens, Marsh Wren is dark above, pale underneath, with a dark brown cap. Field guides emphasize the presence of a strong whitish supercilium, or "eyebrow," and a pattern of light and dark stripes on the upper back, but both these marks can be hard to see in the field. Marsh Wren is unlikely to be confused with any other bird, however. It's clearly a wren, and no other wren is likely to be present in precisely the same habitat. The other very common wren in Sonoma County is Bewick's Wren (Thyromanes bewickii), a bird of scrubby areas, stream-side woods, and other woodland habitats, unlikely to be found in reeds, but it may be distinguished also by it's larger size, longer tail, lack of striping on the back, bolder supercilium, and very different vocalizations (compare below).
Further reading:
Bolander and Parmeter, Birds of Sonoma County California, rev. ed., 2000, p. 94
Brinkley, National Wildlife Federation Field Guide to Birds of North America, 2007, p. 350
Burridge, ed., Sonoma County Breeding Bird Atlas, 1995, p. 128
Dunn and Alderfer, eds., National Geographic Field Guide to the Birds of North America, 5th ed., 2006, p. 344
Dunn and Alderfer, eds., National Geographic Field Guide to the Birds of North America, 6th ed., 2011, p. 386
Dunne, Pete Dunne’s Essential Field Guide Companion, 2006, pp. 483-484
Ehrlich, Dobkin, and Wheye, The Birder's Handbook, paperback edition, 1988, p. 442
Fix and Bezener, Birds of Northern California, 2000, p. 291
Floyd, Smithsonian Field Guide to the Birds of North America, 2008, p. 344
Kaufman, Field Guide to Birds of North America, 2000, p. 290
Kaufman, Field Guide to Advanced Birding, 2011, pp. 94
Lukas, Bay Area Birds: From Sonoma County to Monterey Bay, 2012, pp. 219-220, 265
Parmeter and Wight, Birds of Sonoma County California, Update (2000-2010), 2012, p. 56
Peterson, Birds of Eastern and Central North America, 5th ed., 2002, p. 240
Peterson, Field Guide to Birds of Western North America, 4th ed., 2010, p. 280
Peterson, Western Birds, 3rd ed., 1990, p. 264
Sibley, Field Guide to Birds of Western North America,1st ed., 2003, p. 328
Stokes, Stokes Field Guide to the Birds of North America, 1st ed., 2010, p. 538
Vuilleumier, American Museum of Natural History, Birds of North America: Western Region, 2011, p. 305
Voice: Cornell Lab of Ornithology: All About Birds--Marsh Wren
Voice: Cornell Lab of Ornithology: All About Birds--Bewick's Wren
© Colin Talcroft, 2009, 2010, 2012, 2013, 2014
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.
Marsh Wren--exceedingly well camouflaged. This bird repeatedly struck an odd posture with its tail raised beyond vertical, almost touching its head, probably part of courtship display.
Marsh Wren, Ellis Creek Water Treatment Facility, Petaluma, April 18, 2013
Marsh Wren
Cistothorus palustris
1990-2013 Sonoma County data. Graph provided by eBird (www.ebird.org), generated July 19, 2013
EBird reported occurrence in Sonoma County
Marsh Wren, Ellis Creek Water Treatment Facility, Petaluma, November 16, 2013