Tricky Bird ID: American Tree Sparrow and Chipping Sparrow
The winter plumages of Chipping Sparrows and American Tree Sparrows look very similar. The ranges of these species typically overlap only during migration, but Chipping Sparrows seem to be increasingly found north of their traditional winter range. The usually reliable distinguishing mark–a breast spot on the tree sparrow where there is none on the Chipping Sparrow–can be deceptively unreliable.
Field Marks
American Tree Sparrow
This sparrow (6.25″ long, 16 cm) looks similar in summer and winter. It has a rusty cap and a rusty eye line, a bicolored bill, and a breast spot that is sometimes hidden.
Chipping Sparrow
In summer this slightly smaller sparrow (5.5″ long, 14 cm) has a chestnut cap, a distinct white eyebrow and black eyeline, and a dark bill. However, in winter the striping is much duller, the chestnut cap is typically obscured, and the bill may look pink.
American Tree Sparrow
Cinnamon rust year-round with faint gray streak down middle in winter.
Chipping Sparrow
In winter more tan/brown than rufous with some streaking.
American Tree Sparrow
Rusty brown eyeline.
Chipping Sparrow
Black or dark brown eyeline.
American Tree Sparrow
Bi-colored bill, dark upper mandible, yellow lower mandible.
Chipping Sparrow
Pinkish bill in winter.
American Tree Sparrow
Grayish breast with central, isolated, breast spot (sometimes hidden)
Chipping Sparrow
Grayish breast with no breast spot
American Tree Sparrow
Rusty patch on shoulder
Chipping Sparrow
Plain gray shoulder
American Tree Sparrow
Two white wing bars
Chipping Sparrow
Two buffy wing bars
Learn More
The Cornell Lab of Ornithology’s All About Birds website contains detailed species accounts and cool facts, as well as photographs and paintings from a variety of sources. Visit the online guide pages for American Tree Sparrow and Chipping Sparrow to learn more about both species.