Wilson's WarblerCardellina pusilla

adult male, Pacific
Glenn Bartley/VIREO
adult female, Pacific
Joe Fuhrman/VIREO
juvenile, Pacific
Brian E. Small/VIREO
adult male, Eastern
Garth McElroy/VIREO
adult female, Eastern
Claude Nadeau/VIREO
juvenile, Eastern
Barth Schorre/VIREO
adult female, Pacific
Brian E. Small/VIREO
Wilson's Warbler
Wilson's Warbler

Family

Description

4 1/2-5" (11-13 cm). Adult male olive green above and yellow below, with black crown patch. Most females and all young birds lack black crown and may be distinguished from other olive green warblers with yellow underparts by lack of wing bars, streaks, tail spots, or other markings.

Voice

A rapid, staccato series of chips, which drop in pitch at the end.

Listen

songs #1
alarm chips
songs #3
songs #6
songs #4

Habitat

Moist thickets in woodlands and along streams; alder and willow thickets and bogs.

Range

Breeds from Alaska eastward to Newfoundland and south to southern California, New Mexico, central Ontario, and Nova Scotia. Winters in tropics.

Discussion

It is easy to observe this common warbler, which has little fear of humans, because it searches the outsides of leafy branches, often catching flying insects on the wing like a flycatcher. During early summer, the foraging male utters long bursts of vivid song. It is named for Scottish-American ornithologist and artist Alexander Wilson (1766-1813).

Nesting

4 or 5 brown-spotted white eggs in a bulky mass of leaves, rootlets, and moss, lined with hair and fine plant materials, concealed on the ground in a dense clump of weeds or sedge.

Similar Species

adult male, Interior West, breeding

Yellow Warbler

4 1/2-5" (11-13 cm). Bright yellow with a light olive green tinge on back. Male has fine rusty streaks on breast. The only largely yellow warbler with yellow spots in the tail (not white).

adult male

Kentucky Warbler

5 1/2" (14 cm). Olive green above, bright yellow below; black forecrown, lores, and sides of throat; bright yellow "spectacles." No wing bars. Sexes similar.

adult male

Prothonotary Warbler

5 1/2" (14 cm). Male golden-orange with blue-gray wings; no wing bars; large white spots in tail. Female similar but duller.

adult male (breeding)

Blue-winged Warbler

4 1/2" (11 cm). Sexes similar, mostly bright yellow with blue-gray wings, 2 white wing bars, and black line through eye. Greenish back and tail.

adult male, breeding

Canada Warbler

5" (13 cm). Solid gray above, without wing bars, yellow below; yellow "spectacles"; black-spotted "necklace" on breast. Female similar but duller, with only a trace of necklace.

adult male

Hooded Warbler

5 1/2" (14 cm). Olive above, yellow below. Male has yellow face, black hood and black throat. Female lacks hood or has only a trace of it. Both sexes have white tail spots. See Bachman's Warbler.

Vireo

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