Bell's vireo
Vireo bellii
TAXONOMY
Vireo bellii Audubon, 1844.
OTHER COMMON NAMES
French: Viréo de Bell; German: Braunaugenvireo; Spanish: Vireo de Bell.
PHYSICAL CHARACTERISTICS
4 in (11 cm). A relatively small and dull-colored vireo, with olive-gray upperparts, white underneath, a broken (or incomplete) white eye-ring, and faint whitish wing-bars.
DISTRIBUTION
Breeds in the southwestern and central United States and south to parts of northern Mexico; winters from Baja California to Honduras.
HABITAT
Shrubby vegetation, such as thickets of willows and mesquite, especially in riparian habitat near streams and rivers.
BEHAVIOR
A migratory species that defends a breeding territory. The song is a loud, high-pitched, melodious series of simple phrases.
FEEDING ECOLOGY AND DIET
Feeds actively on invertebrates in foliage, flowers, and limb surfaces. Also eats small berries when invertebrates are not abundant.
REPRODUCTIVE BIOLOGY
Builds a small, cup-shaped nest that hangs from a fork in a tree branch. Lays three or four eggs, incubated by both parents for about 14 days.
CONSERVATION STATUS
Not threatened by IUCN criteria; relatively widespread and abundant. Some populations are threatened by habitat loss due to agriculture, mining, flood-control projects, and reservoir construction. In 1986, the U.S. Fish and Wildlife Service placed a subspecies, the least Bell's vireo (Vireo bellii pusillus), on the U.S. Endangered Species List. The Fish and Wildlife Service regulates human activities in riparian habitat used by the least Bell's vireo in southern California and elsewhere in its range.
SIGNIFICANCE TO HUMANS
None known.
