Family: Vireonidae, Vireos view all from this family
Description ADULT Has greenish upperparts overall; marginally darker wings have two pale wing bars, lower one brighter and more distinct than upper. Dark eye has white supercilium and white "eyelid" below creating incomplete spectacled effect. Underparts are pale overall but washed buffy yellow. JUVENILE Similar to adult.
Dimensions Length: 4 3/4 -5" (12-13 cm)
Endangered Status The Least Bell's Vireo, a subspecies of Bell's Vireo, is on the U.S. Endangered Species List. It is classified as endangered in California. This little vireo lives in dense, streamside willow thickets from southern California into Baja California. The alteration of its habitat, caused mainly by water diversion practices, was a major factor in this vireo's decline. The stresses of habitat loss made the bird vulnerable to other factors. One of these is nest parasitism by cowbirds, which lay their eggs in the vireos' nests. The cowbird young crowd and starve out their hosts smaller offspring. There are thought to be about 300 breeding pairs of Least Bell's Vireos surviving.
Habitat Local and generally rather scarce summer visitor (mainly Apr-Aug) to dense, riverine woodland and scrub across the Midwest. Winters in Mexico.
Observation Tips Listen for its distinctive song.
Range Plains, Southeast, Great Lakes, Texas, Southwest, Florida, California
Voice Song is a rapid, chattering chewee-cheweed'de'de'der; call is a thin chee.
Discussion Active, but highly secretive, warblerlike vireo. Feeds mainly on insects, foraging among dense foliage in a deliberate manner. Western birds (found outside range of this book) are paler and grayer than eastern birds (described in detail below). Sexes are similar.