Vireo flavifrons

With its bright yellow plumage, the Yellow- throated Vireo is one of the most distinctive North American vireos. This woodland edge breeder is uncommon throughout its summer range. Breeding activity is harder to confirm than for low-nesting, cryptically-plumaged vireos (Compare the percentage of confirmed records on the map below with the map in the Gray Vireo [Vireo vicinior] account.) Rodewald and James 1996).

DISTRIBUTION. TBBA data from 1987- 1992 show breeding evidence was found for Yellow-throated Vireo most densely in the Pineywoods region and more widely scattered in a swath extending southwest to the Edwards Plateau (see Lockwood and Freeman [2004] for a map of the biogeographic regions of Texas).

The TBBA map is similar to one based on North American Breeding Bird Survey (BBS) data. Observers found Yellow-throated  Vireos on 27 routes in Texas with highest relative abundances of 1-3 vireos per 40 km (25 mi) route in the Pineywoods region, decreasing from there to <1 per route in the rest of the breeding range (Sauer et al. 2055).

East and north of Texas Yellow-throated Vireo breeds from Manitoba, southern Ontario and southern Quebec south to the Gulf Coast. The species winters in Middle America, northwestern South America and the Bahama Islands (Rodewald and James 1996, Sauer et al. 2005).

SEASONAL OCCURRENCE. Yellow- throated Vireo arrives in Texas from about March 6 to May 22 with most migrants present between late March and mid-May. Breeding occurs from early April to mid-July; eggs have been found from April 15 to June; and Yellow-throated Vireos were seen feeding a fledgling Brown-headed Cowbird (Molothrus ater) on July 13. The species moves south from July 17 to November 23. Most migrants are present between early August and late October. (Oberholser 1974,  Lockwood and Freeman 2004).

BREEDING HABITAT. Yellow-throated Vireo breeds in Texas from near sea level to about 600 m (1900 ft) and prefers tall deciduous riparian trees (Oberholser 1974). The nest is suspended from a fork of a narrow tree branch, often near the trunk and usually 9-18 m (30-60 ft) above ground. It  is a thick-walled, deep cup of grasses and strips of inner bark,  woven together with spider silk and plant down. It is decorated with moss and lichens and lined with fine grasses. The nest rim curves in.

The female usually lays 4 (range 3-5) white to cream white eggs. The parents share incubation duties for 14 days, and the young birds leave the nest about 13 days of age when they can only fly weakly. This species is an acceptor of Brown-headed Cowbird eggs.Cowbirds often remove some or all vireo eggs and parasitized nests average only 0.6 young (Harrison 1979, Rodewald and James 1996).

STATUS. Lockwood and Freeman (2004) describe Yellow-throated Vireo as a common to uncommon summer resident. The TBBA map is similar to the distribution of breeding sites on the map in Oberholser (1974), suggesting no major range changes occurred between 1950 and 1990. BBS population trend data (Sauer et al. 2005) suggest any population change since 1966 in Texas has been minor. The 95% confidence interval for Texas (There is a 95% chance that the actual population trend will be between these two numbers.) is -2.6 to +3.0% per year. The corresponding trend for the total breeding range of the species is an encouraging, statistically significant +1.1%, derived from 1269 routes. These data suggest   Yellow-throated Vireo will continue as a member of the Texas avifauna in the future.

Literature cited.

Harrison, H. H. 1979. A field guide to western birds’ nests. Houghton Mifflin, Boston, MA.Lockwood, M. W. and B. Freeman. 2004. The TOS handbook of Texas birds. Texas A&M University Press, College Station.

Oberholser, H. C. 1974. The bird life of Texas. University of Texas Press, Austin.

Rodewald, P. G. and R. D. James. 1996. Yellow-throated Vireo (Vireo flavifrons). In The birds of North America, No. 247 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

Sauer, J. R., J. E. Hines, and J. Fallon. 2005. The North American Breeding Bird Survey, results and analysis 1966-2004. Version 2005.1. USGS Patuxent Wildlife Research Center, Laurel MD (Web site, http://www.mbr-pwrc.usgs.gov/bbs).