Blue-winged Warblers breed in shrublands, scrubby areas, thickets, and forest edges. During migration they rest and forage in open woodlands, shrublands, thorn forests, gardens, and parks. On the wintering grounds they frequent evergreen and tropical deciduous forest and edge, scrubby areas, and hedgerows; often associating with mixed-species flocks.Back to top
Blue-winged Warblers eat caterpillars, crickets, grasshoppers, spiders, flies, ants, and beetles, which they often pick from clusters of dead leaves while dangling upside down in chickadee-like fashion.Back to top
Females select a spot on or near the ground to build a nest near the boundary between forest and scrub. Females frequently place the nest at the base of goldenrods, berry shrubs, or clumps of grasses or sedges.
Females build an open cup nest of grasses, bark shreds, and dead leaves, which she lines with finer plant material. Nest building takes 2–4 days on average.
|Clutch Size:||2-7 eggs|
|Number of Broods:||1 brood|
|Egg Length:||0.6-0.7 in (1.5-1.7 cm)|
|Egg Width:||0.4-0.5 in (1.1-1.3 cm)|
|Incubation Period:||10-11 days|
|Nestling Period:||8-10 days|
White with small spots of brown or gray near large end.
|Condition at Hatching:||Downy and helpless.|
Blue-winged Warblers move with quick flights and short hops through scrubby vegetation. They tend to forage at the tips of branches often hanging upside down to pick insects from leaves. Males begin establishing territories shortly after arriving on the breeding grounds, but they don't tend to return to the same breeding areas in successive years. Intruding males are met with aggressive posturing, tail spreading, harsh chipping, and chasing. Once females arrive, males chase them around, and the females may chip in response. Courting birds may raise their crowns, flick and spread their tails, and chase each other around, sometimes locking bills. Pairs are thought to be monogamous, but like other warblers, they likely take part in extrapair copulations. Blue-winged Warbler nests are commonly parasitized by Brown-headed Cowbirds, which lay their eggs in warblers' nests. The warbler then unwittingly ends up raising a cowbird chick, most often at the expense of her own chicks.Back to top
Blue-winged Warblers are common, but their populations declined 22% between 1970 and 2014, according to Partners in Flight. The estimated global breeding population is 710,000. The species rates a 13 out of 20 on the Continental Concern Score, which means it is not on the Partners in Flight Watch List and is a species of low conservation concern. In the late 1800s, Blue-winged Warbler populations expanded northward as agricultural fields were abandoned and forest clearcuts started regrowing. This northward expansion increased the frequency of contact with Golden-winged Warblers, a Partners in Flight Red Watch List species, as well as hybridization between the two species. Hybridization and competition between Golden-winged and Blue-winged Warblers is partially responsible for declining populations of Golden-winged Warblers. Although Blue-winged Warblers have expanded their range northward, suburban developments are reducing the amount of second growth and scrub habitat in some locations, which may be responsible for local declines in Blue-winged Warblers.Back to top
Blue-winged Warblers do not visit feeders and may only stop off in your yard during migration, but you can still provide habitat for them in your yard by landscaping with native trees and shrubs. Creating a bird-friendly backyard can provide excellent stopover habitat to support warblers as they migrate to and from the breeding grounds. Head on over to Habitat Network to learn about which native species are good matches for your yard and more.Back to top
Dunne, P. (2006). Pete Dunne's essential field guide companion. Houghton Mifflin Harcourt, New York, USA.
Gill, Frank B., Ronald A. Canterbury and John L. Confer. 2001. Blue-winged Warbler (Vermivora cyanoptera), 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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