The plump and chipper White-throated Sparrow provides an attractive, sweet-voiced presence in suburban yards and country fields across most of the eastern and southern U.S. during winter, retreating to the woods of Canada and the northern fringe of the American Midwest and Northeast to nest.
Two equally numerous color morphs interbreed and exhibit some intriguing behavioral differences: something to cue into whether you’re watching a flock along some thicketed forest edge or massed around your feeder.
Appearance and identification
White-throated Sparrows belong to the North American sparrow genus Zonotrichia, the members of which tend to be fairly large sparrows; indeed, the biggest true sparrow on the continent, Harris’s Sparrow, belongs to Zonotrichia. The White-throated, though, is the smallest – and among the stockiest – of the Zonotrichia species found north of Mexico, usually weighing less than an ounce. It’s typically about 6.5 to 7 inches in length and spreads an 8- or 9-inch wingspan.
As with many sparrows, juveniles of the White-throated can easily be confused with those of close relatives, but adults are fairly distinctive if you can get a good bead on them. The body is a sparrow-typical rufous and brown mass with white- and black-streaked wings and a mottled, grayish belly. The vividly marked head, though, is diagnostic, not least due to the namesake feature: a white throat crisply demarked by dark lines. The crown comes patterned with either boldly contrasting black and white stripes or slightly less boldly contrasting black and tan stripes.
Those plumage variations reflect among the more interesting aspects of the White-crowned Sparrow, which we teased in the introduction: The bird comes in two color morphs, the tan-striped and white-striped, which are roughly coequal in the population. The self-explanatory colors referenced in these names refer to the stripes on the sides of the sparrow’s head as well as the supercilium, or “eyebrow.” The white-striped form also has a brighter yellow lore (area between the eye and the bill) as compared to the tan-striped’s duller one. To some extent, the tan-striped morph resembles first-winter White-throated Sparrows of both varieties.
White-striped White-throated Sparrows (there’s a mouthful) tend to be marginally larger than their Tan-striped counterparts. As we mentioned, color morphs also distinguish themselves in the behavioral department – including when it comes to romantic pairing-up – which we’ll get into shortly.
At a quick glance, the White-throated Sparrow may be confused with its close relative the White-crowned Sparrow, which overlaps with the other in range but tends to be more common in western North America. The White-crowned Sparrow, however, lacks the snowy throat and has a brighter, orange-ish bill compared to the White-throated’s dark gray one. More subtly, White-crowned Sparrows grow a bit larger and lankier than their cousin.
It’s not all that common, but White-throated Sparrows are known to occasionally hybridize with Dark-eyed Juncos, producing a bird grayer and more drably marked than a pure-blooded White-throated. (The two species aren’t especially closely related, but Dark-eyed Juncos are in the sparrow family.)
Location & habitat
In summer, White-throated Sparrows nest in conifer or hardwood stands of North America’s boreal and northern mixed-hardwood forests: mostly Canada but also the Upper Midwest and Northeast of the U.S. Such nesting habitat typically comes with a heavy understory. In winter, the bird roams much of the southern and eastern U.S. and down into northern Mexico, favoring hedgerows, brush, groves, yard- and garden-scapes, and city parks. As with many songbirds, White-throated Sparrows flock together in winter – sometimes with other sparrow species or juncos as well – and establish a clear social hierarchy.
Migrating White-throated Sparrows may be encountered just about anywhere in the Lower 48 east of the Rockies, though the western reaches see much lower numbers.
What do White-throated Sparrows eat?
The winter diet of the White-throated Sparrow is dominated by seeds of grasses and forbs, while in the summer nesting season arthropods–insects such as ants, flies, beetles, caterpillars, and wasps as well as spiders and millipedes–become the most important food. In spring, the sparrows will readily fill up on buds and blossoms; from late summer to early winter, they consume a lot of berries as well.
White-throated Sparrows enthusiastically frequent backyard feeders with millet, sunflower seeds, and the like.
Away from the feeder, White-throated Sparrows search for food by hopping about on the ground or flitting up into shrubs or the low-slung branches of trees.
Communication and call song
The classic song of the White-throated Sparrow, which may be monotone or shift pitch on the second or third note, is often captured by the following mnemonics: Oh-sweet-Canada-Canada-Canada or Poor-Sam Peabody-Peabody-Peabody (sometimes without the extra “Canadas” or “Peabodies” at the end). You can hear this song both on nesting and wintering grounds. Both white-striped males and females sing, and they do so more than tan-striped males; tan-striped females don’t normally sing.
The alarm and aggression calls of the White-throated Sparrow tends to be a short, crisp pink; the birds may issue a longer, higher-pitched seep in flight.
Nesting and mating/eggs and young
Male White-throated Sparrows are aggressively territorial during the breeding season. Both male and female white-striped morphs tend to be more aggressive than their tan-striped neighbors. Mated pairs usually include one of each color morph, though there’s room for different combinations: According to the Cornell Lab of Ornithology, some evidence suggests males of both white- and tan-striped morphs prefer white-striped females, while both white- and tan-striped females prefer tan-striped males.
The female of the pair builds the nest, typically on the ground shielded by dense vegetation or propped in upturned roots or low-set branches not far above it. (The sparrows may be more likely to build an off-the-ground/arboreal nest if the first one is ravaged by a predator.) She’ll build a nest cup with moss, scaffold it with pine needles, twigs, and heavy grass, then line it with softer plant materials or animal hair. The clutch usually consists of three to six eggs; incubation lasts some 11 to 14 days. Both parents feed the young, which spend a week or two in the nest before fledging. (The National Audubon Society suggests tan-striped sparrows feed their young more frequently than white-striped ones, incidentally – another behavioral quirk of the color morphs.)
Sources
- American Bird Conservancy: White-throated Sparrow.
- Cornell Lab of Ornithology. All About Birds: White-throated Sparrow.
- National Audubon Society. Guide to North American Birds: White-throated Sparrow.
- Sibley, David Allen. 2000. The Sibley Guide to Birds. Alfred A. Knopf.