American Tree Sparrow
Look for the American Tree Sparrow on the edge of lawns and shrubby vegetation at Salter Grove during the winter months. Most sightings have been in the parking lot area rather than in the woods. They are likely to hop along on the ground, or perch on food plants to dislodge seeds. Recent Christmas Bird Counts from Massachusetts suggest that their numbers have been declining in the Bay State, so a sighting at Salter Grove would be a great treat indeed.
Even though the American Tree Sparrow has a large dark spot on its breast, the rufous cap and otherwise unmarked underparts indicate that it is not the larger Song Sparrow, the common resident sparrow species in the park.
Be aware that the American Tree Sparrow is nonetheless difficult to identify. It can be confused with the Chipping Sparrow which also has unmarked underparts and a rufous cap. However, the American Tree Sparrow is larger, has a rufous rather than black line through its eye, a dark smudge on its breast and a distinctive two-toned beak. Another potential misidentification can be the pinkish-brown Field Sparrow which has a light rufous cap and eyeline, a clearly defined eyering, and a pink beak
The American Tree Sparrow breeds in scrubby tundra in northern North America from Alaska to northern Quebec and winters in southernmost Canada and the northern part of the United States. Although it will perch in small shrubs, it builds a ground nest as well as mostly forages on the ground. It was probably misnamed as a tree sparrow because it looked like the Eurasian Tree Sparrow to the early settlers.
During the breeding season, the American Tree Sparrow will feed exclusively on insects. However, on its wintering grounds, it mostly feeds on the small seeds produced by grasses, sedges, ragweed, knotweed, and goldenrods, as well as berries and catkins and the occasional insect egg or larva. They will visit feeders for smaller seeds like millet, especially when scattered on the ground.