What to look for to tell apart Lincoln's Sparrow and Song Sparrow
Published: February 24, 2012
Most streaky sparrows live in open fields or marshes. A streaky sparrow in dense thickets will usually turn out to be a Song Sparrow. Because Song Sparrow is so widespread, you may take it for granted and thus overlook a similar and subtle relative: Lincoln’s Sparrow.
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Unlike Song Sparrows, which often nest in backyards, Lincoln’s Sparrows are summer birds of boreal zones from Alaska to eastern Canada and at high elevations in mountains of the West. They occur as migrants throughout the lower 48 states, wintering commonly along the Pacific coast and in the Southwest, less commonly east to Florida. Despite their wide distribution, they are distinctly less numerous from the Great Plains eastward, and eastern birders often miss them altogether.
Habitat and behavior can be major clues, both for finding and for identifying Lincoln’s Sparrows. They seek out dense low cover at all seasons, often foraging on the ground inside thickets or forest. In migration, they may pause at sites where cover is limited, even in city parks, and they may forage in the open, but when disturbed, they dive into the nearest shrubbery. Even when numbers are present, the birds do not form cohesive flocks. We could generalize by calling them solitary, secretive skulkers.
Face pattern holds many clues, too. On Lincoln’s, the gray eyebrow (supercilium) contrasts with the rich brown lateral crown stripe. A narrow, buff eye-ring is sometimes obvious. Below and in front of the ear coverts, the whisker mark (submoustachial stripe) is rich buff and set off from the white center of the throat by a lateral throat stripe broken up into fine dark streaks.
Unfortunately, Song Sparrows can duplicate many of these points. They often show a gray eyebrow, and many have a distinct eye-ring or buff in the whisker mark. Their lateral throat stripe tends to be much more solid and darker. A better distinction, though, is the pattern of the underparts. Lincoln’s Sparrows have neat, fine, pencil-thin streaks on a background of rich buff on the chest and similar streaks extending down the olive-buff flanks. Broader, heavier streaks always mark the underparts of adult Song Sparrows.
Note that the last sentence specified adult Song Sparrows. A tricky summertime problem involves young Song Sparrows, out of the nest but not molted out of juvenile plumage yet: Their streaks can be much finer than those of adults, and they can be buffy below, so they are sometimes mistaken for Lincoln’s.
What to look for
Behavior and habitat.
Solitary and skulking, typically staying low in dense thickets.
Chest pattern. Fine, pencil-like streaks on buff background; sometimes aggregated into central spot.
Face pattern, lower half. Broad whisker mark consistently warm buff, set off on lower edge by lateral throat stripe made up of very fine streaks.
Face pattern, upper half. Eyebrow consistently gray, contrasting against rich brown lateral crown stripes, and sometimes against narrow buff eye-ring.
Lower underparts. Lower breast and belly unmarked grayish white; flanks olive-buff, marked with fine dark streaks.
Eastern birders who have trouble tracking down Lincoln’s Sparrow can take comfort in the fact that they are in good company, in a historical sense.
John James Audubon described the species in 1834. He had discovered it in Labrador the previous year, and he named it for Thomas Lincoln, a young assistant on the trip. It was one of the prized finds of the expedition.
Here’s the kicker, though: By the time Audubon discovered the sparrow, he had already spent years in its range. He had lived in Pennsylvania and Kentucky and Louisiana, and he had sought birds all over the eastern states. Lincoln’s occurs regularly in migration or winter in all these areas, but he had never noticed it. Neither had Alexander Wilson, who had scoured the same regions while researching his American Ornithology. Nor had any of the other early explorer-naturalists. Not until Audubon reached the nesting grounds and heard the sparrow’s sweet, melodious song did he realize that it was something different.
Even on its nesting territory, the new sparrow was not easy to pin down. Audubon and his companions were in Labrador almost three weeks before they consciously heard the song. When they pursued the bird, Audubon wrote, “we found more wildness in this species than in any other inhabiting the same country.” Eventually they were able to observe it, but Audubon never did learn where it went in the non-breeding season. Birdwatchers today, with the advantage of more information, can seek it during every migration season.
Kenn Kaufman is the author of the Kaufman Guide to Birds of North
America, Kaufman Field Guide to Advanced Birding, and other books about
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