American Tree Sparrow or Field Sparrow?

General appearance

The American tree sparrow is a small, slender bird with a distinct rusty cap and gray face. A notable brown streak extends through the eye, and the bird has a bicolored bill with a dark upper mandible and yellow lower mandible. Its back and wings are brown with dark streaks, while the underparts are pale gray with a central dark spot on the breast. The tail is long and notched with two white wing bars that stand out.

Male vs female

There is minimal sexual dimorphism in American tree sparrows, meaning males and females look alike. Both genders share the same coloration and markings, making them difficult to distinguish based solely on appearance.

Juvenile

Juvenile American tree sparrows resemble adults but with slightly duller and less distinct markings. Young birds may have a more muted crown and face pattern. As they mature, their plumage becomes more defined, resembling the adults in coloration and characteristics.

Primary habitat

The American tree sparrow primarily dwells around treelines where the northern forest transitions into tundra, typically within Arctic scrub and willow thickets or in clearings in stunted spruce forests.

Additional range

Unexpectedly, this bird species also inhabits open fields, woodland edges, marshes, and suburban areas during winter. They frequent brushy roadsides and areas with tall shrubs.

Natural diet

The American tree sparrow's diet varies seasonally. In winter, it primarily consumes seeds from grasses, weeds, and other plants, while occasionally eating a few insects and berries. During summer, its diet shifts to mostly insects and other small invertebrates, supplemented by a few seeds. The young sparrows are mostly fed insects, providing the necessary nutrition for growth.

Bird feeders

At bird feeders, the American tree sparrow often eats seeds, particularly favoring sunflower seeds, millet, and other small seeds commonly available in bird seed mixes. These food sources help supplement their natural diet, especially during the winter months when food is scarce.