Black-Capped Vireo Scientific Name: Vireo Atricapillus Federal Status: Endangered, 10/6/87• State Status: Endangered

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. increases in predation by dogs, cats, raccoons, skunks, and jays, have also Where To See the impacted the vireo. Black-capped Vireo A number of state lands offer oppor- Recovery Efforts tunities to see and learn more about Research is underway to better under- the Black-capped Vireo. These Habitat at Kickapoo Caverns State Park © Matt Wagner stand the distribution, life history, include Colorado Bend State Park habitat requirements, and land man- State Park (SP), Devils River State agement practices affecting the Black- Natural Area (SNA), Kerr Wildlife capped Vireo. Population surveys Management Area, Kickapoo Cavern during the breeding season are being SP, Lost Maples SNA, and Hill Country conducted in known and potential SNA. Also, the Balcones Canyonlands habitat areas. Efforts to provide National Wildlife Refuge near Austin information and educational opportu- offers additional opportunities to see nities to landowners and the public Black-capped Vireos. regarding life history and habitat Because the Black-capped Vireo requirements of the vireo are also a is an endangered species, birders and vital part of the recovery effort. other observers should carefully fol- Major research and/or recovery low certain viewing ethics. Habitat with low-growing shrubs © Matt Wagner efforts are being conducted on Observers should be careful not to Department of Defense’s Fort Hood flush birds from the nest or disturb and Camp Bullis, Travis County and nests or young. Black-capped Vireos the City of Austin’s Balcones Canyon- should be viewed only from a dis- lands Preserve, the U.S. Fish and tance with binoculars. Do not use Wildlife Services’ Balcones Canyon- recorded calls of the Black-capped lands National Wildlife Refuge, Vireo or the Screech Owl to attract TPWD’s Kerr Wildlife Management birds, and be careful that your pres- Area, properties owned and/or man- ence does not unduly disturb or aged by The Nature Conservancy of stress the birds. Texas, and in Mexico. Additionally, Environmental Defense through their How You Can Help Safe Harbor Agreement with the U.S. You can help by learning more about Fish and Wildlife Service is assisting the habitat requirements of the Black- many landowners with thousands of capped Vireo and incorporating man- Habitat in Big Bend National Park © USFWS A. Shull acres to manage and/or create habitat agement practices which create or for the benefit of the vireo. Research maintain habitat for these birds. You egg or a nestling from the host nest is ongoing regarding the impact of can also encourage and support pri- before she lays an egg in it. Cowbird cowbirds on vireo populations in vate landowners who are managing chicks hatch earlier than most hosts’s Texas. Research efforts in Mexico are their land to protect and provide habi- young and are thus able to out-com- also underway to gather information tat for endangered species. pete the smaller vireo nestlings for concerning life history, habitat The Black-capped Vireo is a food and, consequently, the young requirements, and conservation beautiful songbird and is much vireos typically starve. While some threats on the wintering range. sought after among people who enjoy birds remove cowbird eggs from their TPWD biologists are monitoring pop- birdwatching and nature study. Possi- nest, the vireo does not, although it is ulations on both state and private bilities exist for landowners to take known to abandon parasitized nests. lands, and voluntary cowbird trap- advantage of the growing demand for Thus parasitized nests usually fail to ping is being conducted by more than natural history tours and vacations. produce vireos. The amount of brood 400 landowners in counties through- Landowners interested in more infor- parasitism varies greatly from one out the range of the vireo. mation concerning nature-based population to another throughout the Habitat conservation planning is tourism opportunities should contact state, ranging from 10 to over 90% of underway in counties such as Travis the Wildlife Diversity Branch, Texas the nests. Brown-headed Cowbirds and Bexar to allow for urban expan- Parks and Wildlife Department, are also known to remove vireo sion and development while still con- Austin (800) 792-1112; Environmen- chicks from active nests. Evidence serving endangered species habitat. tal Defense, Austin (512) 478-5161; indicates that sustained parasitism Intensive monitoring of a large popu- the Nature Conservancy, San Antonio pressure may lead to local extinctions lation at the U.S. Army Fort Hood (210) 224-8774. of vireo populations. Military Installation is on-going. Direct habitat loss and fragmen- Finally, efforts to provide information, tation due to urban and suburban technical assistance, and incentives for Black-capped Vireo 3 You can also be involved with the conservation of Texas’ nongame wildlife resources by supporting the Special Nongame and Endangered Species Conservation Fund. Special nongame stamps and decals are avail- able at Texas Parks and Wildlife Department (TPWD) field offices, most state parks, and the License Branch of TPWD headquarters in Austin. Part of the proceeds from the sale of these items is used to con- serve habitat and provide informa- tion to the public concerning endangered species. Conservation organizations in Texas also welcome your participation and support. For More Information Contact Texas Parks and Wildlife Department Wildlife Diversity Branch 4200 Smith School Road Austin, Texas 78744 (512) 912-7011 or (800) 792-1112 or Cowbird egg (spotted) in Black-Capped Vireo nest U.S. Fish and Wildlife Service © Glen Mills Ecological Services Field Office 10711 Burnet Road, Suite 200 Austin, Texas 78758 References (512) 490-0057 Armstrong, W.E., M.W. Lockwood, and D.K. Stuart. 1992. Performance report: Black-capped vireo management on Texas Parks and Wildlife Department Management guidelines are available lands. Federal Aid Project No. E-1-4, Job No. 3.2. from the Texas Parks and Wildlife Armstrong, W.E., C. Travis, and B.G. Alexander. 1989. Final report: Black-capped Department and U.S. Fish and vireo management. Federal Aid Project No. W-103-R-19, Job No. 60. Wildlife Service for landowners and Farquhar, C.C. and J. P. Maresh. 1998. Population biology and habitat characteri- managers wishing to know more zation of black-capped vireos at Dolan Falls Ranch Preserve, Val Verde about rangeland management prac- County, Texas. Year two final report. Endangered Resources Branch, Texas Parks and Wildlife Department. Austin, Texas. tices which improve habitat for the Graber, J.W. 1961. Distribution, habitat requirements, and life history of the Black-capped Vireo. black-capped vireo. Ecol. Mon. 31:313-336. Grzybowski, J.A., R.B. Clapp, and J.T. Marshall, Jr. 1986. History and current population status of the Black-capped vireo in Oklahoma. American Birds 40:1151-1161. Grzybowski, J,A., D.J. Tazik, and G.D. Schnell. 1994. Regional analysis of black- capped vireo breeding habitats. Condor 96:512-544. Grzybowski, J.A. 1995. “Black-capped vireo (Vireo atricapillus).” The birds of North America, No. 181. The Academy of Natural Sciences, Philadelphia, and The American Ornithologist Union, Washington D.C. Oberholser, H.C. 1974. The bird life of Texas. Edgar Kincaid, Ed., University of Texas Press, Austin, Texas. Vol. 2, 1069 pp. Robinson, S.K., S.I. Rothstein, M.C. Brittingham, L.J. Petit, and J.A. Grzybowski. 1995. “Ecology and behavior of cowbirds and their impact on host popula- tions” (pp 428-460) in T.E. Martin and D.M. Finch, eds. Ecology and manage- ment of neotropical migratory birds. Oxford University Press, New York, New York. U.S. Fish and Wildlife Service. 1991. Black-capped vireo recovery plan. Endan- gered Species Office, Albuquerque, N.M. U.S. Fish and Wildlife Service. 1996. Black-capped vireo population and habitat viability assessment report. Complied and edited by Carol Beardmore, Jeff Hatfield, and Jim Lewis in conjunction with workshop participants. Report of a September 18-21, 1995 workshop arranged by the U.S. fish and Wildlife Ser- vice in partial fulfillment of U.S. National Biological Service Grant No. 80333- 1423. Austin, Texas. ix + 57 pp.

4 Black-capped Vireo Funds for the production of this leaflet were provided by the U.S. Fish and Wildlife Service, under Section 6 of the Endangered Species Act.