It's a special treat each year when White-crowned Sparrows (Zonotrichia leucophrys) show up in the Great Central Valley. These lively little birds make a lovely winter addition to our local avifauna, and my family sometimes call them "Christmas tree birds," as they remind us of old-fashioned spun cotton bird ornaments. Small and quick, White-crowned Sparrows may first be mistaken for "just another little brown bird," but upon closer inspection you will notice the striking black-and-white stripes on this little bird's head which gave rise to its common name.
White-crowned Sparrows are year-round residents of the Sierra Nevada (and central coast region of California) venturing down-slope into the Central Valley as the weather changes in the fall; they are summer breeders in Alaska and Canada as well, wintering over much of the United States. Preferred habitat includes tangled brushy areas, from true wilderness to city parks and backyards. They are often seen low in bushes and hopping about on the ground, so patches of bare or grassy ground are important habitat features. Their main food source is grass and weed seeds, though they will also feed on berries and insects when they can get them.
Interestingly, Cornell's All About Birds site indicates that although breeding pairs of White-crowned Sparrows spend the winter months apart, about two-thirds of the pairs will re-form the following breeding season.
Look for these pretty little sparrows this winter at your backyard bird feeders as well as out in the wilds, and listen for their beautiful and familiar whistled song, usually the first clue I get that they have returned! (You can also listen to the song of the White-crowned Sparrow on Cornell's site, by following the link here.)