National Geographic Magazine/Volume 31/Number 4/Friends of Our Forests/Blackburnian Warbler
The Warblers of North America
Range: Breeds in lower Canadian and upper Transition Zones from Manitoba, southern Keewatin, central Ontario, Quebec, and Cape Breton Island to central Minnesota, Wisconsin, northern Michigan, Massachusetts, and Connecticut, and in the Alleghenies from Pennsylvania to Georgia and South Carolina; winters from Colombia to central Peru and less commonly north to Yucatan.
The Blackburnian, one of the gems of the warbler tribe, has a rather wide range in eastern North America, extending west as far as the Plains and north to Manitoba. Apparently it is nowhere, at least in migration, an abundant warbler, and there are few field observers so seasoned to the sight of its beautiful colors as not to be thrilled by sight of the bird. In migration its habits offer nothing peculiar. In the Atlantic States in September careful scrutiny of a migrating band of warblers and other birds will often reveal the presence of one or perhaps half a dozen Blackburnians. About Mount Monadnock, Gerald Thayer finds it a “very common summer resident. It is one of the four deep-wood warblers of this region, the other three being the black-throated blue, the Northern parula, and the Canada.”
The Blackburnian favors very big trees, particularly hemlocks, and spends most of its life high above the ground. As Thayer says, the Blackburnian is the “preëminent forest warbler of the group, the lover of deep mixed growth and the upper branches of the biggest conifers.” The bird has a thin, shrill voice and utters at least two songs or variations which some think resemble the black-throated green's. Whatever the tree selected, be it a hemlock or a deciduous tree, the nest is placed well up among the branches and well out toward the end, where it is safe from all enemies that do not possess wings.