For five years, my husband and I covered a Breeding Bird Survey route in Colorado’s high country. One morning during breeding season, starting ½ hour before dawn on a 24.5-mile stretch of road, we stopped the car every half mile for three minutes to count all the birds we saw or heard (mostly heard). Some birds’ songs were so similar that you had to work
to determine, say, whether a Black-headed Grosbeak or an American Robin was singing. Or if you missed the super-high introductory notes, was that song a Ruby-crowned Kinglet or maybe a Warbling Vireo? But one unique song that always made me smile was the melodious, haunting, flute-like song of the Hermit Thrush. This ethereal two-part song—beginning with a long, clear note followed by high, upward-spiraling, twirling notes—rings out. No doubting that songster!
The Hermit Thrush has a rich gray-brown head and back; a warm, reddish-brown tail; distinct spots on its throat; and smudged spots on a white breast. Its chunky shape resembles a fellow thrush, the American Robin, but smaller. With a close look you may see a narrow but still discernible eye-ring. The bird seals its identification with its tail—a quick, upward jerk of the tail, then a slow lowering. Rapid wing-flicks often accompany the single or multiple tail jerks.
During breeding season, the U.S. hosts six spot-breasted thrush species—Veery, Gray-cheeked, Bicknell’s, Swainson’s, Hermit, and Wood thrushes—five of which winter in Central and/or South America. So if you see a spot-breasted thrush in San Diego County or anywhere else in North America between December and March, stop now. Do not pass Go, do not collect $200. The odds are really, really good that you’re looking at a Hermit Thrush.
Hermit Thrushes occur in San Diego County primarily from late September through April, when they leave their more northerly breeding grounds. During the winter, Hermit Thrushes become common here in chaparral and riparian or oak woodland. They also appear in modified habitats such as orchards, parks, and yards with plentiful shrubbery. The census of wintering Hermit Thrushes in the county fluctuates somewhat from year to year, due to variation in the numbers reaching the county, food availability, and the depth of the snow cover in the mountain chaparral.
These thrushes energetically glean insects and berries from branches near the ground. They also lift leaf litter with their beaks, tossing it aside to expose the ground. They sometimes forage by “foot quivering,” where they shake bits of grass with their feet to uncover insects. They have been known to capture small amphibians and reptiles as well.
Hermit Thrushes breed in mature coniferous and hardwood forests, mixed forest, and riparian canyons stretching as far north as northern Canada. Historically, the southern limit of the breeding range of the Hermit Thrush was the San Bernardino Mountains. Thanks to survey work for the San Diego County Bird Atlas 20−30 years ago, summering Hermit Thrushes have now been documented, along with the first confirmations of breeding, in San Diego County around Palomar, Hot Springs, Volcan, and Cuyamaca mountains.
Although celebrated for its exquisite, far-reaching song, the Hermit Thrush lives up to its common name. This quiet and unobtrusive bird spends much of its time alone in the shadows and lower branches of the undergrowth or on the forest floor. The term “thrush” arises from Middle English thrusch, the name for this type of bird. Catharus guttatus, the scientific name, draws from both Greek and Latin. The genus name arises from Greek catharos, meaning “spotless, pure, ”which references the sharp, brown spots on crisp, white plumage. The species name, guttatus, comes from Latin for “spotted, speckled as with raindrops,” also referring to the spotted breast of this bird.
For the next month or so, look for these winter thrushes locally in berry-filled thickets and woodlands as well as well-vegetated parks and residential areas. Come spring and summer, if you are lucky enough to be in the mountains with breeding Hermit Thrushes, open your ears. A woodland concerto by this avian songster announces the presence of the “American nightingale.”