Season Tweetings – Nature’s Winter Serenade
Fee odi-odi zeeee-zaaaa-zoooo. Nope. Seee zreee chidli-chidli chi-chi-chi. Not that either. See sitli-sitli ti-ti-ti-ti-zrrrr. Good grief, not even close. Let’s face it. Humans really can’t recreate this avian song on paper—a sorry statement about our language limitations rather than a reflection of this lilting song.
Generally in early to mid-November, this familiar song—a long, clear whistle followed by a jumble of quick buzzy notes— fills the air, always making me smile. Most birds quit singing by August, so nearly any song this time of year catches my ear. This song also brings back fond memories of summer hiking in the high-altitude mountains of Colorado, where it accompanies every step. The first scouts of this species begin to arrive in our area in mid-September and you might hear their songs occasionally. By November, though, they seem to be singing everywhere. The wintering White-crowned Sparrows have arrived in force!
Your first glance at a White-crowned Sparrow registers it as a plain, pale-gray bird. But your eye quickly catches the small, pale pink or yellow bill and bold black and white stripes on its head. (My husband calls them “badger-heads.”) These two features combine with the crisp gray breast for a dashing look—and make it one of the easiest sparrow identifications in North America. (And we need all of those we can get.) Immatures resemble adults although the distinctive head pattern is a more muted one of brown and tan stripes. Watch for flocks of these sparrows scurrying through brushy borders and overgrown fields. You can often coax them into the open with backyard feeders too.
The White-crowned Sparrow’s scientific name (Zonotrichia leucophrys) refers to the bird’s distinctive head pattern. The genus name means “banded thrush,” from the Greek zone (“belt,” for the bands on the head) and trikhas (“song thrush”), honoring the distinctive song. The species name, leucophrys, means “white eyebrow,” from Greek leukos (“white”) and ophrus (“eyebrow”), for the white stripe above the eye.
By November, White-crowned Sparrows seem almost ubiquitous, being rare only at the county’s highest elevations. The species often ranks as San Diego County’s most abundant sparrow during this five-month stay. Some grass, weeds, or open ground for foraging, with nearby shrubbery or trees for predator protection, are this bird’s only winter requirements. As a result, coastal sage or desert scrub, broken chaparral, woodland edges, urban parks, and weedy areas can all host White-crowned Sparrows. They often gather in large flocks, making them seem even more numerous.
As breeding season approaches, rising hormone levels in male birds prompt increased singing. As breeding season draws to a close in late summer, the waning daylight triggers decreased hormone levels—a response referred to as photosensitivity—and singing drops off. But White-crowned Sparrows are photorefractory in the autumn and early winter, exhibiting no hormonal changes with the diminishing day length. As a result, males sing throughout the year, using their winter songs to establish and maintain the social structure of the large flocks that roam the new winter territory in search of food.
With the influx of these sparrows, we get front-row seats to a quiet, off-season symphony. Come spring, these sprites pack their bags and back to their northern breeding grounds. By mid-April, the species becomes uncommon again. So listen to a few recordings (such as the one under “Typical Voice” here), tune up your ears, and enjoy this winter songster while you can.