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 Northeast, 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.Back to top
Yellow-rumped Warblers eat mainly insects in the summer, including 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. On migration and in winter they eat great numbers of fruits, particularly bayberry and wax myrtle, which their digestive systems are uniquely suited among warblers to digest. The habit is one reason why Yellow-rumped Warblers winter so much farther north than other warbler species. Other commonly eaten fruits include juniper berries, poison ivy, poison oak, greenbrier, grapes, Virginia creeper, and dogwood. They eat wild seeds such as from beach grasses and goldenrod, and they may come to feeders, where they'll take sunflower seeds, raisins, peanut butter, and suet. On their wintering grounds in Mexico they've been seen sipping the sweet honeydew liquid excreted by aphids.Back to top
Yellow-rumped Warblers put their nests on the horizontal branch of a conifer, anywhere from 4 to about 50 feet high. Tree species include hemlock, spruce, white cedar, pine, Douglas-fir, and larch or tamarack. They may build their nests far out on a main branch or tuck it close to the trunk in a secure fork of two or more branches. Occasionally nest are built in a deciduous tree such as a maple, oak, or birch.
Females build the nest, sometimes using material the male carries to her. The nest is a cup of twigs, pine needles, grasses, and rootlets. She may also use moose, horse, and deer hair, moss, and lichens. She lines this cup with fine hair and feathers, sometimes woven into the nest in such a way that they curl up and over the eggs. The nest takes about 10 days to build. It's 3-4 inches across and about 2 inches tall when finished.
|Clutch Size:||1-6 eggs|
|Number of Broods:||1-2 broods|
|Egg Length:||0.7-0.8 in (1.7-2.1 cm)|
|Egg Width:||0.5-0.6 in (1.3-1.5 cm)|
|Incubation Period:||12-13 days|
|Nestling Period:||10-14 days|
|Egg Description:||White, speckled with brown, reddish-brown, gray, or purplish gray.|
|Condition at Hatching:||Helpless and naked with sparse brown down. Eyelids have dull white spots.|
Yellow-rumped Warblers flit through the canopies of coniferous trees as they forage. They cling to the bark surface to look for hidden insects more than many warblers do, but they also frequently sit on exposed branches and catch passing insects like a flycatcher does. In winter, Yellow-rumped Warblers join flocks and switch to eating berries from fruiting shrubs. Sometimes the flocks are enormous groups consisting entirely of Yellow-rumped Warblers. If another bird gets too close, Yellow-rumped Warblers indicate the infraction by holding the body horizontally, fanning the tail, and raising it to form a right angle with its body. When males court females, they fluff their feathers, raise their wings and the feathers of the crown, and hop from perch to perch, chipping. They may also make display flights in which they glide back and forth or fly slowly with exaggerated wingbeats. The Yellow-rumped Warbler's flight is agile and swift, and the birds often call as they change direction.Back to top
Yellow-rumped Warblers are common and widespread, and populations have held steady from 1966 to 2019, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 170 million and rates them 6 out of 20 on the Continental Concern Score, indicating a species of low conservation concern. Like many migrating birds, Yellow-rumped Warblers are frequently killed in collisions with radio towers, buildings, and other obstructions.Back to top
Dunne, P. (2006). Pete Dunne's essential field guide companion. Houghton Mifflin Harcourt, New York, USA.
Dunn, J. L., and K. L. Garrett (1997). A Field Guide to the Warblers of North America. Houghton Mifflin Company, Boston, MA, USA.
Ehrlich, P. R., D. S. Dobkin, and D. Wheye (1988). The Birder's Handbook. A Field Guide to the Natural History of North American Birds, Including All Species That Regularly Breed North of Mexico. Simon and Schuster Inc., New York, NY, USA.
Hunt, Pamela D. and David J. Flaspohler. (1998). Yellow-rumped Warbler (Setophaga coronata), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.
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