Breeding Bird Atlas 2 Results

See all of the BBA2 data to date on the USGS BBA Explorer.

Preliminary Results:
Hermit Thrush: Spreading East and South

Latin Name: Catharus guttatus
Breeding Habitat: Northern forests
Massachusetts Status: Increasing

Hermit Thrushes can be found breeding throughout the northern forests from New England to Alaska as well as in much of the Rocky Mountains and the western United States. Its voice, lilting and ethereal, has won it admiration all across this extensive breeding range.

Although they are traditionally thought of as birds of the deep woods (hence “hermit”), Hermit Thrushes are proving to be quite adaptable in their selection of breeding territory.

Hermit Thrushes have a long and illustrious history in New England, so much so that the Hermit Thrush is the state bird of Vermont. The extensive forests of Massachusetts, particularly the Pitch Pine forests of the southeastern coastal plain, were a haven for Hermit Thrushes.

Clearing of the land reduced their numbers, and to see or hear a Hermit Thrush was a rare treat a century ago. When surveys began for Atlas 1, Hermit Thrushes were re-establishing themselves in former strongholds across the state as the forests grew up once more.

Unsurprisingly, Berkshire County hosted plenty of breeding Hermit Thrushes, as did Franklin and Hampshire Counties. Hermit Thrushes were a bit scarcer in Hampden and Worcester, scarcer still in Middlesex, and quite uncommon in Essex, Norfolk, Suffolk, and Bristol.

Plymouth and Barnstable Counties had a decent number of records, and breeding was even confirmed on Martha’s Vineyard. Conifer forests are preferred, but clearly Hermit Thrushes are also willing to nest in mixed woods as well. Hermit Thrushes aren’t readily colonizing suburbia just yet, but they do seem to be making their homes in fragmented and disturbed forests in Atlas 2.

Clearly the thrushes still favor large forests, when they are available; western Massachusetts is definitely the place to be if you’re a Hermit Thrush. Even so, they’re experiencing an upswing in the eastern part of the state, or at the very least, they aren’t decreasing.

Hermit Thrushes arrive earlier in the spring than their fellow forest thrushes, usually appearing on territory in late April and early May. The male’s song is a series of sweetly whistled tinkling phrases which rise and fall without an appreciable pattern. The nest, which is usually located on the ground, is woven together using twigs, grasses, and strips of bark. The inside cup is often lined with fine rootlets, pine needles, mosses, and other soft materials. The female incubates the 3-6 eggs for about 12 days.

Although Hermit Thrushes regularly consume fruit when it’s available, their diet when breeding is mainly invertebrates and small amphibians. These protein-rich foods are an ideal diet for the rapidly growing young, which must be ready to leave the nest just 12 days after hatching. These fledglings can fly short distances, but primarily hop along the ground while following their parents on foraging forays.

Hermit Thrushes can and do raise two broods, where conditions permit, and it’s not unusual to find parents feeding nestlings well into August. Hermit Thrushes do not winter as far south as most of our other thrushes, and so proceed south for the winter at a leisurely pace. Migration extends from October through December, but a non-trivial number of Hermit Thrushes remain in Massachusetts through the winter, occasionally visiting backyard suet feeders in the company of American Robins.