Bell's VireoVireo bellii
DESCRIPTION
4 3/4 -5" (12-13 cm). Smaller than a sparrow. Dull olive-gray above, whitish below, with faint white eye ring and fainter wing bars. White-eyed Vireo similar but larger, with yellow "spectacles" and white eyes.
VOICE
Fast, warbled tweedle-deedle-dum? tweedle-deedle-dee! First phrase up, second phrase down.
HABITAT
Dense bottomland thickets, willow scrub, and mesquite.
RANGE
Breeds from southern California, Colorado, Dakotas, and Indiana southward. Absent from eastern third of United States. Winters in tropics.
DISCUSSION
The species was named by Audubon for John G. Bell (1812-1899), a New York taxidermist who accompanied him on his trip up the Missouri River in the 1840s. Incubating Bell's Vireos, like other vireos, are so fearless around their well-camouflaged nests that an observer may photograph them from a few feet away. The strong, somewhat curved beak, with a slight hook at the end, like a miniature of a shrike's beak, reminds us that these birds, however gentle they seem, are determined predators. They feed on caterpillars, aphids, various larvae, and spiders. Although often victimized by cowbirds, this bird raises relatively few of the brood parasites, simply abandoning a nest when a cowbird's egg is laid in it.
NESTING
3-5 white eggs, sparsely marked with brown, in a well-made pendant cup of plant down and bark strips, placed in a dense tree or shrub.
CONSERVATION STATUS
The Least Bell's Vireo (Vireo bellii pusillus), a subspecies of Bell's Vireo, is on the U.S. Endangered Species List.
