Black-capped Vireo
Encyclopedia
The Black-capped Vireo, Vireo atricapilla, is a small bird
native to the United States
and Mexico
. It has been listed as an endangered species
in the United States since 1987. The IUCN lists the species as vulnerable.
The Black-capped Vireo is a songbird
about 12 cm (4.5 inches ) in length. Sexually mature males are olive green above and white below with faint yellow flanks. The crown and upper half of the head is black with a partial white eye-ring and lores. The iris is brownish-red and the bill is black. Females are duller in color than males and have a slate gray crown and underparts washed with greenish yellow. First year males are intermediate in coloration between adult males and females.
The male and female in a pair assist in nest construction and incubation. The female broods the young, while the male supplies most of the food during the nestling phase. Typically, three or four eggs are laid. The incubation
period is 14 to 17 days, and the nestling period is 10 to 12 days. Breeding pairs are capable of producing more than one clutch per breeding season. The male cares for some or all of the fledglings, while the female re-nests - sometimes with another male. These birds are insectivorous, with beetle
s and caterpillar
s making up a large part of the diet.
Black-capped Vireos nest in "shinnery," brushy areas with scattered trees. Shinneries primarily consist of shin oak or sumac. Appropriate height and density are important factors for this species' breeding success. Junipers seem to be of little or no importance. Foliage that extends to ground level is the most important requirement for nesting. Most nests are between 15 and 50 inches (35–125 cm) above ground level and are screened from view by foliage. Territories are sometimes located on steep slopes, where trees are often clumped and intermediate in height. On level terrain, preferred Black-capped Vireo habitat is a mixture of shrubs and smaller trees that average from eight to 10 feet high (2.5-3.5 m). Black-capped Vireos will no longer use sites where many trees are nearing full size.
The historic breeding distribution of the Black-capped Vireo extended south from south-central Kansas
through central Oklahoma
and Texas
to central Coahuila
, Mexico
. At present, the range extends from Oklahoma south through the Edwards Plateau
and Big Bend National Park
, Texas, to at least the Sierra Madera in central Coahuila, Mexico. In Oklahoma, the Black-capped Vireo is found only in Blaine, Cleveland, and Comanche counties. The winter range of this vireo
is not well known. It is thought to winter along the west coast of Mexico from southern Sonora
to Guerrero
.
(Molothrus ater) brood parasitism
, human disturbance, and loss of habitat to urbanization, fire exclusion, grazing, and brush control.
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
native to the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. It has been listed as an endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
in the United States since 1987. The IUCN lists the species as vulnerable.
The Black-capped Vireo is a songbird
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
about 12 cm (4.5 inches ) in length. Sexually mature males are olive green above and white below with faint yellow flanks. The crown and upper half of the head is black with a partial white eye-ring and lores. The iris is brownish-red and the bill is black. Females are duller in color than males and have a slate gray crown and underparts washed with greenish yellow. First year males are intermediate in coloration between adult males and females.
The male and female in a pair assist in nest construction and incubation. The female broods the young, while the male supplies most of the food during the nestling phase. Typically, three or four eggs are laid. The incubation
Avian incubation
Incubation refers to the process by which certain oviparous animals hatch their eggs, and to the development of the embryo within the egg. The most vital factor of incubation is the constant temperature required for its development over a specific period. Especially in domestic fowl, the act of...
period is 14 to 17 days, and the nestling period is 10 to 12 days. Breeding pairs are capable of producing more than one clutch per breeding season. The male cares for some or all of the fledglings, while the female re-nests - sometimes with another male. These birds are insectivorous, with beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
s and caterpillar
Caterpillar
Caterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...
s making up a large part of the diet.
Black-capped Vireos nest in "shinnery," brushy areas with scattered trees. Shinneries primarily consist of shin oak or sumac. Appropriate height and density are important factors for this species' breeding success. Junipers seem to be of little or no importance. Foliage that extends to ground level is the most important requirement for nesting. Most nests are between 15 and 50 inches (35–125 cm) above ground level and are screened from view by foliage. Territories are sometimes located on steep slopes, where trees are often clumped and intermediate in height. On level terrain, preferred Black-capped Vireo habitat is a mixture of shrubs and smaller trees that average from eight to 10 feet high (2.5-3.5 m). Black-capped Vireos will no longer use sites where many trees are nearing full size.
The historic breeding distribution of the Black-capped Vireo extended south from south-central Kansas
Kansas
Kansas is a US state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa Native American tribe, which inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south...
through central Oklahoma
Oklahoma
Oklahoma is a state located in the South Central region of the United States of America. With an estimated 3,751,351 residents as of the 2010 census and a land area of 68,667 square miles , Oklahoma is the 28th most populous and 20th-largest state...
and Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
to central Coahuila
Coahuila
Coahuila, formally Coahuila de Zaragoza , officially Estado Libre y Soberano de Coahuila de Zaragoza is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. At present, the range extends from Oklahoma south through the Edwards Plateau
Edwards Plateau
The Edwards Plateau is a region of west-central Texas which is bounded by the Balcones Fault to the south and east, the Llano Uplift and the Llano Estacado to the north, and the Pecos River and Chihuahuan Desert to the west. San Angelo, Austin, San Antonio and Del Rio roughly outline the area...
and Big Bend National Park
Big Bend National Park
Big Bend National Park is a national park located in the U.S. state of Texas. Big Bend has national significance as the largest protected area of Chihuahuan Desert topography and ecology in the United States, which includes more than 1,200 species of plants, more than 450 species of birds, 56...
, Texas, to at least the Sierra Madera in central Coahuila, Mexico. In Oklahoma, the Black-capped Vireo is found only in Blaine, Cleveland, and Comanche counties. The winter range of this vireo
Vireo
The vireos are a group of small to medium-sized passerine birds restricted to the New World. They are typically dull-plumaged and greenish in color, the smaller species resembling wood warblers apart from their heavier bills...
is not well known. It is thought to winter along the west coast of Mexico from southern Sonora
Sonora
Sonora officially Estado Libre y Soberano de Sonora is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided into 72 municipalities; the capital city is Hermosillo....
to Guerrero
Guerrero
Guerrero officially Estado Libre y Soberano de Guerrero is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 81 municipalities and its capital city is Chilpancingo....
.
Conservation
The Black-capped Vireo is threatened by Brown-headed CowbirdBrown-headed Cowbird
The Brown-headed Cowbird is a small brood parasitic icterid of temperate to subtropical North America. They are permanent residents in the southern parts of their range; northern birds migrate to the southern United States and Mexico in winter, returning to their summer habitat around March or...
(Molothrus ater) brood parasitism
Brood parasite
Brood parasites are organisms that use the strategy of brood parasitism, a kind of kleptoparasitism found among birds, fish or insects, involving the manipulation and use of host individuals either of the same or different species to raise the young of the brood-parasite...
, human disturbance, and loss of habitat to urbanization, fire exclusion, grazing, and brush control.
External links
- Black-capped Vireo photo gallery - VIREO
- Photo-High Res--(Close-up); Article - Society for Conservation Biology
- Black-capped Vireo video with song
- BirdLife Species Factsheet.
