This morning, while driving along a country road, I encountered a flock of American tree sparrows, scouring the gravel for seeds. These attractive songbirds, easily identified by their rusty cap and central breast spot, are winter residents across the northern two-thirds of the Lower 48.
Despite their name, American tree sparrows breed across the Arctic tundra and adjacent scrublands; in fact, they breed farther north than any other American sparrow. Nests are placed directly on the ground and adults forage primarily on grasslands or in thickets and shrubs. Insects and seeds are consumed while they are in the Arctic but their diet is limited to seeds on their wintering grounds.
Indeed, these hardy sparrows migrate south rather late in the fall and are among the first songbirds to head north in the spring (often by early March). On the other hand, they are fairly common here during the winter months; just don't look for them in trees!
