Wilsonia pusilla
(Wilson's Warbler)

Order: Passeriformes
Order Description: Passerines
Family: Parulidae
Family Description: Wood Warblers

Physical Description:
4 1/2-4 3/4" (11-12 cm). Black crown; yellow below and on head and napeClick word for definition; olive-green back and wings; dark eyes. Females have duller crownClick word for definition.

Similar Species- Female Yellow Warbler

A short, chattering trill, dropping in pitch.

Breeds from portions of Alaska and Canada, south to southern California, central Nevada, northern Utah, northern New Mexico, northern Minnesota, and portions of upper New England. Winters occasionally along Gulf Coast and southern Texas, throughout most of Mexico, and commonly in Central America.

Found in open areas in moist woodlands, in bogs with scattered trees, and in willow and alder thickets. During winter, found in semi-open or lightly-wooded areas, in canopies, openings, and edges of forest, and in second growth, coffee plantations, brushy fields, and yards.

Feeds on insects such as wasps, ants, flies, beetles, and caterpillars.

Builds nest on ground. Forages throughout available vegetation, obtaining most food from leaves by gleaning while perched or flying. Usually solitary and territorial in winter, but may join mixed flocksClick word for definition. California study found territory size in different habitats ranged from about 0.2-2.2 ha.

clutchClick word for definition size is commonly 3-4 eggs in coastal California, 4-5 in Sierra Nevada, and 5-6 in Alaska. Incubation lasts about 12-15 days; female incubatesClick word for definition eggs. Young are tended by both parents, and leave nest at 9-10 days (California). In Sierra Nevada, some males are polygynousClick word for definition.

Element Code: ABPBX16020
Status: Protected nongame species
Global Rank: G5
State Rank: S5,NTMB
National Rank: N5B

Important State References:
Douglas, D.C., J.T. Ratti, R.A. Black, and J.R. Alldredge. 1992. Avian habitat associations in riparian zones of Idaho's Centennial Mountains. Wilson Bull. 104:485-500.

Design by Ean Harker©1999, 2000.
Written by Jason Karl, 2000.