American Tree Sparrows
These fairly large, handsome sparrows breed in the high tundra of the Canadian north, but when winter comes they flock eagerly to weedy fields and backyard feeders across Massachusetts. Sometimes known as “winter chippies” for their resemblance to overgrown chipping sparrows, American tree sparrows are active and sociable.
American tree sparrows are large-bodied and long-tailed, which makes them look a little larger than most other sparrows that visit feeders. Their backs are reddish brown with plenty of streaking along the edges of their feathers, but the best field marks for this species are the cap and the chest. American tree sparrows have a bright chestnut cap, as well as a matching chestnut line through the eye. Their plain breasts have no streaks but often show a small smudge or spot in the center.
Contrary to their name, American tree sparrows do much of their feeding on the ground, where they hop about looking for seeds. Their flocks keep up a constant exchange of high, musical two-note calls see-weep, see-weep, see-weep. When waiting their turn at the feeder or fleeing from predators, American tree sparrows will perch in trees or low shrubs. They will often flutter to a seed-laden grasshead (or bird feeder) and flap their wings vigorously, trying to knock seeds to the ground.
American tree sparrows do not breed in Massachusetts, but they are very common migrants and winter residents. Unfortunately, Christmas Bird Count data indicate that a possible decline in winter numbers may be taking place in the Bay State.