The Yellow-rumped WarblerSetophaga coronata consists of four closely related North American bird forms—the eastern Myrtle Warbler (ssp coronata), its western counterpart, Audubon's Warbler (ssp group auduboni), the northwest Mexican Black-fronted Warbler (ssp nigrifrons), and the Guatemalan Goldman's Warbler (ssp goldmani)—are periodically lumped as the Yellow-rumped Warbler.
Yellow-Rumped Warblers are some of the earliest Warblers to arrive and latest to leave The Yellow-rumped Warbler breeds from eastern North America west to the Pacific, and southward from there into Western Mexico. "Goldman's" Yellow-rumped Warbler is endemic to the highlands of Guatemala. The Myrtle and Audubon's forms are migratory, traveling to the southern U.S., Mexico, Central America, and the Caribbean for winters. Among warblers it is one of the last to leave North America in the fall, and among the first to return. It is an occasional vagrant to the British Isles and Iceland.
Yellow-rumped Warblers spend the breeding season in mature coniferous and mixed coniferous-deciduous woodlands (such as in patches of aspen, birch, or willow). In the western U.S. and in the central Appalachian Mountains, they are found mostly in mountainous areas. In the Pacific Northwest and the Northeastern U.S., they occur all the way down to sea level wherever conifers are present. During winter, Yellow-rumped Warblers find open areas with fruiting shrubs or scattered trees, such as parks, streamside woodlands, open pine and pine-oak forest, dunes (where bayberries are common), and residential areas. On their tropical wintering grounds they live in mangroves, thorn scrub, pine-oak-fir forests, and shade coffee plantations.
In summers, males of have streaked backs of black on slate blue, white wing patches, a streaked breast, and conspicuous yellow patches on the crown, flank, and rump. Audubon's Warbler also sports a yellow throat patch, while the Myrtle Warbler has a white throat and eye stripe, and a contrasting black cheek patch. Females of both forms are more dull, with brown streaking front and back, but still have noticeable yellow rumps. Goldman's Warbler, of Guatemala, resembles Audubon's but has a white lower border to the yellow throat and otherwise darker plumage; males replace the slate blue of Audubon's with black.
These birds are one of North America's most abundant neotropical migrants. They are primarily insectivorous. The species is perhaps the most versatile foragers of all warblers. Beyond gleaning from leaves like other New World warblers, they often flit, flycatcher-like, out from their perches in short loops, to catch flying insects. Other places Yellow-rumped Warblers have been spotted foraging include picking at insects on washed-up seaweed at the beach, skimming insects from the surface of rivers and the ocean, picking them out of spiderwebs, and grabbing them off piles of manure. Common foods include caterpillars and other larvae, leaf beetles, bark beetles, weevils, ants, scale insects, aphids, grasshoppers, caddisflies, craneflies, and gnats, as well as spiders. They also eat spruce budworm, a serious forest pest, during outbreaks. Wikipedia