Black-capped Vireo Scientific Name: Vireo atricapillus Federal Status: Endangered, 10/6/87• State Status: Endangered Description central and southwest Texas, a few leaved plants in vireo habitat in these The Black-capped Vireo is a 4.5 inch counties in central Oklahoma, and in regions include: Texas (Spanish) oak, insect-eating songbird. Mature males Coahuila and Nuevo Leon, Mexico, Lacey oak, shin oak, Durand (scaley- are olive green above and white although less is known of their status bark) oak, live oak, mountain laurel, below with faint greenish-yellow in Mexico. Black-capped Vireos winter evergreen sumac, skunkbush sumac, flanks. The crown and back of the along the western coast of Mexico. flameleaf sumac, redbud, Texas per- head is black with a partial white eye- The descriptions of habitat pre- simmon, Mexican buckeye, elbowbush ring. The iris is brownish-red and the sented in this document are intended and agarita. Although Ashe juniper is bill black. The plumage on the back to help landowners determine if they often part of the plant composition in of the female is duller than the male. have Black-capped Vireo habitat on vireo habitat, preferred areas usually Females have a medium to dark gray their property. Not all sites within have a low density and cover of head with a blackish ring around the the habitat types described will be juniper. used by Black-capped Vireos. It is In the western Edwards Plateau only where individuals of this species and Trans-Pecos Regions, on the west- occupy the identified habitat types ern edge of the vireo’s range, the during the breeding season that spe- birds are often found in canyon bot- cial management considerations such toms and slopes where sufficient as those provided in these guidelines moisture is available to support need to be considered. diverse shrub vegetation. Dominant In Texas, vireo habitat is found woody plants in this habitat type on rocky limestone soils of the include sandpaper oak, Vasey oak, Edwards Plateau, Cross Timbers and Texas kidneywood, Mexican walnut, Prairies, eastern Trans-Pecos and, to a Texas persimmon, lotebush, brasil, limited extent, on igneous soils in the wafer ash, mountain laurel, cenizo, Male Black-capped Vireo © TPWD Chisos Mountains. Although Black- whitebrush, and guajillo. capped Vireo habitat throughout Texas is highly variable with regard to plant species, soils, temperature, and rainfall, all habitat types are sim- ilar in vegetation structure; i.e. the “overall look” is somewhat similar although the plant species vary. Vireos require broadleaf shrub vegetation reach- ing to ground level for nesting cover. They typi- cally nest in shrublands and open woodlands with a distinc- tive patchy structure. Typical habi- tat is characterized by shrub vegetation extending from the ground to about 6 feet or more and covering about 30-60% or greater of the total Female Black-capped Vireo © USFWS A. Shull area. In the eastern portion of the vireo’s range, the shrub layer is often For all habitat types, the plant white surrounding the eye (this gener- combined with an open, sparse to composition appears to be less impor- ally distinguishes the female from the moderate tree canopy. Patches of tant than the presence of adequate second year male). open grass or bare rock separate the broad-leaved shrubs, foliage to ground clumps of shrubs and trees. In central level, and mixture of open grassland Distribution Texas, this habitat is often regrowth and woody cover. Deciduous and and Habitat from disturbances such as clearing, broad-leaved shrubs and trees through- Historical records from 1852-1956 fire, and browsing. out the vireo’s range are also impor- show that the Black-capped Vireo In the Edwards Plateau and Cross tant in providing habitat for insects on once occurred and nested from cen- Timbers Regions, vireo habitat occurs which the vireo feeds. tral Kansas, Oklahoma, Texas and where soils, topography, and land use into northern Mexico. Today, Black- produce scattered hardwoods with capped Vireos are known to nest in abundant low cover. Common broad- Black-capped Vireo 1 Life History nearby. The birds migrate to their win- Black-capped Vireos arrive in Texas tering grounds on Mexico’s western from mid-March to mid-April. Adult coast beginning in July, and are gone males often arrive before females and from Texas by mid-September. first-year males to select their territo- ries. Vireos’ territories are often clus- Threats and Reasons tered in patches of suitable habitat. for Decline Although territories range in size The Black-capped Vireo is vulnerable from 1 to 16 acres, most territories to changes in the abundance and qual- are 5 to 10 acres. Males sing to ity of its habitat. Habitat may become attract mates and defend territories. unsuitable for vireos because of nat- Many males can be heard singing ural plant succession, sustained brood throughout the breeding season, but parasitism by the Brown-headed Cow- singing begins to decline by July. The bird, or because of human activities. vireo’s song is described as hurried Factors that can adversely affect vireo and harsh, composed of numerous habitat include broad-scale or phrases separated from one another improper brush clearing, fire suppres- by pauses of 1 to 3 seconds. sion, over browsing by deer and live- Nesting begins after the females stock, and urbanization. Loss of Black-capped Vireo nest arrive in late March to early April. tropical wintering habitat is also a © TPWD Glen Mills Both the male and female select the concern, but requires further study. nest site and build the nest, but the Poorly planned brush manage- female often completes it. First nests ment practices on rangeland may are built in about 6 to 9 days, but remove too much low growing woody subsequent nests can be built in one cover, especially when large acreages day. The cup-shaped nest is sus- are treated at one time. This elimi- pended from its rim in a fork of a nates or reduces habitat value for branch about 1 to 6 feet above the vireos and for other wildlife, such as ground. However, most Black-capped White-tailed deer, quail, small mam- Vireos nest at about “door-knob” mals, and various songbirds. Over height. Nests have been found in a browsing of broad-leaved shrubs by variety of species including shin oak, goats, deer, and exotic animals scalybark oak, Texas oak, Vasey oak, reduces the vegetation in the 2- to sumac, Texas persimmon, juniper, 4-foot zone, making it unsuitable for Texas redbud, Mexican buckeye and vireo nesting. Continued overuse of Texas mountain laurel. these preferred browse plants over The vireo usually nests more than many years may eventually eliminate once in the same year. A new nest is them from the plant community, thus constructed each time. Three to four permanently altering the habitat. eggs are usually laid in the first nest- In the absence of natural ing attempt, but later clutches may processes, active, well-planned land Nesting vireo contain only 2 to 3 eggs. The first egg management is often required to © Greg W. Lasley is usually laid one day after comple- maintain good vireo habitat, espe- Texas. However, the combination of tion of the nest, with one egg being cially in the eastern portion of its overgrazing, brush clearing, and lack laid each subsequent day. Incubation range. Disturbance, particularly fire, of fire in the recent past has reduced takes 14 to 17 days, and is shared by plays an important role in maintain- vireo habitat in many other areas. the male and female. ing, improving, or creating vireo Natural plant succession is less of a Vireo chicks are fed insects by habitat. The rangelands of central concern in the western portion of its both adults. The young leave the Texas, and the various plant commu- range where suitable habitat persists nest 10 to 12 days after hatching. nities these lands support, evolved for long periods. Fledglings are cared for by the female under the influence of periodic fires. Human activities have provided alone, the male alone, or by both Historically, these natural and man- favorable habitat for the Brown- adults. Sometimes the parents split made fires maintained a matrix of headed Cowbird, which parasitizes the brood and each care for one or open grassland, shrubland and wood- vireo nests. The cowbird is usually more young. Occasionally, males or land. Fire stimulated shrubs to associated with livestock, farms, females will leave the care of the sprout multiple stems at the base, dairies, and grain fields, where it ben- young to their mate, and attempt thus providing areas of dense foliage efits from waste grain and insects. another nesting effort. at the 2- to 4-foot level, required by They may also be attracted to back- Vireos may live for more than five vireos. In the past, fire was responsi- yard bird feeders, trash dumps, or years, and usually return year after ble for maintaining or periodically other urban areas where food and year to the same territory, or one returning some areas to vireo habitat. water are available. Cowbirds lay Today, prescribed burning, a valuable their eggs in other birds’ nests, leav- range and wildlife management tool ing the host bird to raise their young. 2 Black-capped Vireo occurs on many ranches throughout The female cowbird often removes an development is a major threat in private landowners to incorporate expanding urban areas of Travis, management for Black-capped Vireos McLennan, Dallas, Bexar, and Kerr into their livestock and wildlife opera- counties. Problems associated with tions are an essential part of the suburban expansion, such as recovery process.