The Indigo Bunting (Passerina cyanea) is a denizen of dense areas of deciduous shrubbery and young trees throughout the spring and summer. Though it is more common than many people realize, its populations are declining in eastern North America, as are the numbers of almost all species dependent on shrublands and very young, regenerating forests.
In spring and summer, the male bunting’s plumage is a stunning cobalt blue, with deep blue flight feathers turning darker, almost black. Its bill and legs are dark gray. The juvenile and adult female plumages are mostly tan with very faint, slightly lighter brown wing bars; a whitish throat, belly, and undertail coverts; and slightly darker brown, faint streaking on the breast and flanks. This makes a female or young Indigo Bunting—reminiscent of a sparrow of some sort—a difficult species to identify for beginner birders.
The male’s song is a loud, ringing series of paired phrases, often rendered, “Fire! Fire! Where? Where? Here! Here!” similar to a goldfinch’s song. When singing, the male is often high up on an exposed perch like the top of a dead tree where, if backlit, he can look blackish from a distance instead of blue. Most of the time, though, Indigo Buntings are closer to the ground. Their nests comprise an open cup of grasses, plant stems, and strips of bark, built about one to three feet from the ground in dense cover. This species is a frequent host of the Brown-headed Cowbird, a brood parasite that lays its eggs in the nests of other birds, leaving them to be raised by the host species.
At the end of the breeding season in fall, bright blue Indigo males start getting blotchy with patches of subtler light brown feathers, their bright “nuptial” plumage no longer needed for the long journey to their wintering grounds in the West Indies, Mexico, and Central America.
You can help bolster Indigo Bunting populations by planting native shrubs, especially berry-bearing varieties, and maintaining old field habitat or plant native meadows. Collisions with cars are also a cause of mortality for the birds, so stay aware while driving in areas with favorable Indigo Bunting habitat.