A small, sprightly vireo; top and sides of head glossy black in male, slate gray in female. Two wing bars. Conspicuous white -spectacles- formed by eye-ring and loral patch; eyes red.
Oak scrub, brushy hills, rocky canyons. Breeds on hot dry hillsides with dense thickets of brush, especially scrub oaks, often with many openings or gaps rather than solid cover. Winters in
Mexico in dense thickets and woodland edges, especially in foothills and lowlands.
Fire suppression is probably the most serious threat, but urban development and agricultural conversion (especially to pasture) have caused significant habitat loss. Intensive grazing has further degraded habitat. Increasing numbers of Brown-headed Cowbirds Molothrus ater has resulted in high rates of brood-parasitism, and rates of nest predation are high; primarily from snakes, fire ants Solenopsis spp. and mammals. The high return rates of birds to breeding territories suggests few threats on the wintering grounds.
Mostly insects, some berries.
Feeds mainly on insects in summer; diet not known in detail, but eats many caterpillars, beetles, small grasshoppers and crickets, and others, as well as spiders. Also eats some berries and small fruits. Winter diet poorly known, but may include more ber
Behavior: Forages more actively than most vireos, moving among branches and twigs in dense cover, sometimes hanging upside down like a chickadee to take items from underside of foliage.
This species qualifies as Vulnerable owing to rapid population declines throughout most of its contracting range. The population is already small and fragmented, but the disappearance of isolated populations and remaining breeding habitat indicate that these rapid declines will continue. [conservation status from birdlife.org]
Male defends territory by singing throughout breeding season. In courtship, male sings while following female; may also perform short song-flight.
Nest: Placed in low scrubby oak or other dense shrub, usually 2-
6 above ground, rarely higher. Both parents help build nest, a small hanging cup suspended in the horizontal fork of a twig. Nest is made of grass, strips of bark, weeds, leaves, bound together with spider webs; inside is lined with fine grass.
Clutch 3-5, usually 4. White, unmarked (most other vireos lay spotted eggs). Incubation, by both parents, averages about 16 days, surprisingly long for such a small bird.
Young: Both parents bring food for nestlings. Young leave the nest about 10-
12 days after hatching and may be cared for by parents for more than another month. Sometimes male is left to care for first brood while female begins second nesting attempt.
Breeds southwestern Kansas (formerly), central Oklahoma, western and central Texas (through Edwards Plateau and Big Bend) to Coahuila, Mexico. Winters in Mexico. Migration:
Generally arrives in Texas in April, departs in September. Migrates toward the southwest in fall, wintering along west coast of Mexico.
- spanwidth min.: 17 cm
- spanwidth max.: 19 cm
- size min.: 10 cm
- size max.: 11 cm
- incubation min.: 13 days
- incubation max.: 14 days
- fledging min.: 10 days
- fledging max.: 12 days
- broods 1
- eggs min.: 3
- eggs max.: 5
- Conservation Status