White-crowned Sparrow

Present year-round, but more common in the winter because our coastal breeding population, the Nuttall's race (Zonotrichia leucophrys nuttalli) is joined by wintering birds from populations that breed far to the north (mostly in Alaska and northwestern Canada, but as far south as northern Idaho and western Montana). Common in the winter in much of the county, favoring lightly wooded edge environments, open brushy areas inland, and scrub along the coast, but not uncommon in parks and in suburban areas. Regular winter feeder visitor. In the summer months, usually present only at the coast. Mostly forages on the ground or in low vegetation. Typically moves in small flocks on the ground or through low trees or brush, often mixed with Golden-crowned Sparrow, our other common winter sparrow of the genus Zonothrichia.

Usually easily recognized by its black-and-white striped crown and yellowish bill. As in the case of Golden-crowned Sparrow, pictures in field guides can be confusing, especially to beginning birders in Sonoma County, because guides often show birds in full breeding plumage and often do not show our Nuttall's race. Our birds are somewhat browner on the breast and flanks than the idealized forms often depicted, and the white striping on the head is usually duller (however, birds with the starkly black-and-white striped heads--suggestive of those old-fashioned leather helmets worn by bicycle racers--are present). From the side, the white stripe at the top of the crown is often not visible, which may give the bird a black-capped look. Otherwise, white-crowned Sparrow is a fairly large sparrow with a comparatively long tail; tweedy brown striped back (like Golden-crowned Sparrow); grey nape; pale grey to pale brownish throat, breast, belly, and flanks; two indistinct, often spotty, whitish or pale wing bars; yellow to orange bill (pinkish--almost terra cotta-colored--in some juveniles); and longish pink legs. First few notes of the song are similar to Golden-crowned Sparrow--a clear, plaintive, low whistling--but these are followed by buzzy, trilled notes.

Five major subspecies are recognized. Zonotrichia leucophrys nuttalli and Z. leucophrys pugetensis are our most common winter residents and the coastal birds that remain in Sonoma County year-round are Nuttalli. Z. l. nuttalli tends to stay near the coast, Z. l. pugetensis will range further inland. These both have smaller, more yellowish bills than either the nominate subspecies, Z. l. leucophrys or Z. l. oriantha, which both have larger, more pinkish bills and a dark area that connects from the front of the eye to the forehead not present in the other subspecies. Subspecies leucophrys inhabits the eastern part of North America and presumably is not normally seen here. Z. leucophrys oriantha is present in the High Sierras, the southern part of the Cascade range as far south as Mt. St. Helens, and into the Rockies, wintering in Mexico and Baja California. These, are not common in Sonoma County, although some are known to winter in the Bay Area at higher elevations (in Sonoma County, mostly Mt. St. Helena). Z. leucophrys gambeli, the fifth subspecies, ranges from Alaska to Hudson's Bay during breeding season but may be present in Sonoma county in the winter months, although these birds tend to stay inland. In practice, most local birders ignore the subspecies distinctions, and nuttalli and pugetensis, in particular, may be difficult to distinguish in the field, although vocalizations of the various groups are distinctive to the trained ear and may be useful with practice. According to the National Geographic field guide, oriantha, pugetensis, and nuttalli give "one or more thin, whistled notes followed by a sweet twittering trill." Leucophrys and gambelii are said to give a "more mournful song with no trill at the end." The guide also notes that the song of nuttalli is especially variable geographically, even over rather short distances. According to Fix and Bezener, ornithologists have done extensive research into bird song variation based on this species.

Young birds are worth studying. They confuse many who see what looks like a reddish-brown cap when viewing young birds from the side (photo below). The yellowish bill shown here is typical of our local birds. To people not used to seeing them, young birds can resemble field guide pictures of Field Sparrow (Spizella pusilla), American Tree Sparrow (Spizella arborea), or Chipping Sparrow (Spizella passerina). American Tree Sparrow is highly unlikely, having been sighted locally only two or three times historically. I find no records of Field Sparrow in the county at all. Chipping Sparrow is rare here in the winter (normally present between late April and early October) and often confined to open areas near woods at higher elevations. Chipping Sparrow in summer plumage has a chestnut crown, strong white eyebrow, and strong, dark eyeline that extends from before to well behind the eye, all lacking in White-crowned Sparrow.