A Bird With A Bright Yellow Belly And Face, Offset By Olive-Green Wings And A Head Capped Off With A Jaunty French Beret!

clonejoe | February 1, 2021 | Articles

A bird in seemingly ceaseless motion, its wings flicking and its tail wagging, is a bird easily identified by its bright yellow belly and face, offset by olive-green wings, with the mal wearing a jaunty French beret.

The Wilson’s Warbler likes to nest in low, dense stands of alders, willows, and various other shrubs. Much like its cousins, the Orange-crowned Warbler and Yellow Warbler.

*Photo Courtesy of Becky Matsubara – CC BY 2.0*

The breeding range for all three species extends much further north than most other warblers, right across much of Alaska and Canada, ranging south down through much of the Rocky Mountains and the Sierra Nevada’s, and down the West Coast into southern California.

During winter the Wilson’s Warbler can mostly be found in Mexico and Central America, with a few hanging out along the Gulf Coast in Texas and Louisana as well as southern California. This makes it a medium-distance migrant.

Currently, there three recognized subspecies of Wilsons Warbler, based on various factors like size, color, and body size. The western birds have the brightest plumage of all and may have diverged enough genetically to actually be recognized as a separate species.

Like almost all wood-warblers, the Wilson’s Warbler is an insectivorous bird, feeding on both adult and larval insects. It will occasionally forage for berries, mainly during winter.

*Photo Courtesy of Mike’s Birds – CC BY 2.0*

The Wilson’s Warbler is seasonally monogamous, although polygyny (when a male mates with more than one female) may be fairly common in mountain populations. In good habitat, this warbler can be found nesting in loose groups with overlapping territories.

*Photo Courtesy of U.S. Fish and Wildlife Service Headquarters – CC BY 2.0*

The female Wilson’s Warbler usually builds her cup-shaped nest of leaves, moss, and rootlets on the ground at the base of a shrub or small tree, concealed by dense vegetation. The Pacific coast population is an exception, usually nesting several feet above the ground amid thick tangles of vines or shrubbery.

*Photo Courtesy of Andy Reago & Chrissy McClarren – CC BY 2.0*

The female lays a clutch of four to six eggs and does most of the incubation. Both parents feed the young, which fledge when they are about 10 days old. Western populations of the Wilson’s Warbler are commonly parasitized by the Brown-headed Cowbird.

Although still common, the Wilson’s Warbler has experienced widespread population declines, particularly in the West, primarily due to loss of riparian habitat.