Measurements
Both Sexes
- Length
- 4.3 in
11 cm - Wingspan
- 7.1 in
18 cm - Weight
- 0.3–0.4 oz
8–10 g
Other Names
- Viréo à tête noire (French)
- Vireo de gorra negra, Vireo de antifaz (Spanish)
Cool Facts
- The Black-capped Vireo is the only vireo that is sexually dimorphic in plumage, where the male and female look different. It also is the only one in which the male takes two years to reach adult plumage.
- Research shows that Black-capped Vireo songs draw from a repertoire of syllables about ten times larger than those of other vireos.
Habitat
Scrub
Low scrub, often on poor or eroded soils, or in areas at an early stage of succession.
Food
Insects
Adult insects, insect larvae, and spiders.
Nesting
Nesting Facts
- Clutch Size
- 2–5 eggs
- Egg Description
- Smooth and white.
- Condition at Hatching
- Naked and pink, with eyes closed.
Nest Description
Open hanging cup, made of leaves, grasses, plant fiber, and animal silk, lined with fine grass.Nest often decorated with spider silk, cocoons, or bits of paper. Cup opening is narrower than nest itself; adult can sit inside nest with only bill and tail tip showing.
Nest Placement
Tree
Behavior
Foliage Gleaner
Gleans from leaves, twigs, and branches. Sometimes hangs upside down or hovers while feeding.
Conservation
Vulnerable
Endangered. Largely extirpated from traditional breeding range in the United States. Cowbird parasitism is a major threat; cowbird removal efforts have evidently led to local increases in Black-capped Vireo populations. Destruction of suitable habitat through urban and suburban development and livestock grazing also have significantly contributed to the species' decline. Habitat maintenance and creation through prescribed burning and other manipulation are a high management priority.
Credits
- Grzybowski, J. A.. 1995. Black-capped Vireo (Vireo atricapillus). In The Birds of North America, No. 181 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, and The American Ornithologists' Union, Washington, D.C.