Yellow-breasted Chats, oversize wood- warblers with varied and unmistakable vocalizations, are more easily heard than seen as they whistle, rattle and emit other weird noises from the middle of a dense bush. In spite of their apparent difference from wood- warblers, genetic studies place the chats within the wood-warblers, although not close to any other species. Yellow-breasted Chat has 2 recognized subspecies, inhabiting eastern and western North America respectively, more or less neatly separated by the Great Plains. The situation in Texas is less clear (Pyle 1997, Eckerle and Thompson 2001).
DISTRIBUTION. During the 1987-1992 field work seasons of the TBBA project, volunteers found 20 confirmed breeding sites, 244 probable and 89 possible sites. The low frequency of confirmed evidence is not surprising since most chat nests are well concealed in dense vegetation.. The densest concentration of sites was in east Texas, covering the Pineywoods and spilling over into the Post Oak Savannah and Blackland Prairies and Coastal Prairies regions (see the region map in Lockwood and Freeman ). This band of breeding sites extends north into Oklahoma, where almost all breeding sites are in the easternmost quarter of the state (Versaw 2004). This area in the two states probably represents the eastern subspecies, I. v. virens. A second subspecies breeds in the western North America and west Texas. (Eckerle and Thompson 2001). Most breeding of the western race in Texas apparently occurs along the Rio Grande River in the Trans-Pecos and spottily on the Edwards Plateau.
The breeding range of the eastern subspecies extends east and north from Texas and Oklahoma to the Atlantic coast, southern Missouri and the Ohio River valley but excluding peninsular Florida. Chats also breed in the west, but in much more scattered sites and lower relative abundances. The species also breeds on the central plateau and in northwest Mexico. Chats winter on both coasts of central Mexico and from south Mexico to north Panama (Howell and Webb 1995, Eckerle and Thompson 2001, Sauer et al. 2005
SEASONAL OCCURRENCE. Most Yellow-breasted Chats arrive in Texas from early April to early May when they are considered uncommon to common throughout the eastern two-thirds of the state. Breeding occurs from early April to mid-August (occasionally later, based on egg dates from April 6 to September 15). Fall migrants are present from mid-August to mid-October (Oberholser 1974, Lockwood and Freeman 2004).
BREEDING HABITAT. In Texas Yellow-breasted Chats breed from near sea level to 1500 m (5000 ft) in a variety of brushy habitats. In western North America; suitable conditions are usually in riparian areas. About 90% of breeding sites in Colorado and Arizona are in riparian areas (Oberholser 1974, Roth and Kingery 1998, Eckerle and Thompson 2001, Corman 2005).
In eastern North America, higher moisture levels allow chats to breed in a greater variety of brushy areas such as overgrown fields, power-line corridors, hedgerows, forest edges and openings, gardens and parks as well as riparian areas (Eckerle and Thompson 2001, Versaw 2004).
The nest is built in dense vegetation about 1 m (3 ft) above ground by the female. The bulky cup is constructed of grass, leaves strips of bark and forb stems and lined with fine roots and hair (Oberholser 1974). The external diameter averages about 14 cm (5.6 in), internal diameter 7.7 cm (3.1 in) and cup depth 5.7 cm (2.3 in Eckerle and Thompson 2001).
The most common clutch is 4 (range 1-6) smooth, white eggs evenly speckled with red-brown to gray or purple. These are incubated by the female for 11-12 days and after hatching, the young birds remain in the nest for 7-10 days. Most chat pairs raise only one brood per season. The most common brood parasites of Yellow-breasted Chats are Brown- headed Cowbirds (Molothrus ater) although Bronzed Cowbirds (M. aeneus) have also been reported to parasitize chats (Harrison 1979, Eckerle and Thompson 2001).
STATUS. In comparison with the map in Oberholser (1974), TBBA atlasers found almost no breeding evidence for extreme south Texas or near the south and central coast. Breeding records also seem more scattered in the Post Oak Savannah and Blackland and Rolling prairies than on the map of historical records, suggesting the range of Yellow- breasted Chat in Texas has shrunk since observations were first made.
Lockwood and Freeman (2004) consider this chat a common to uncommon summer resident in the Trans-Pecos, Edwards Plateau and Pineywoods regions of this. state and TBBA observers found 20 confirmed, 244 probable and 89 possible breeding records for chats, mostly in these regions.
Data from 555 Breeding Bird Survey routes in Texas showed relative abundances as high as 10-30 chats per route in the Pineywoods and southwest Edwards Plateau regions. The data also provide a statistically significant annual population change of +3.9% for the period 1980-2005, compared to a +0.5% change for the whole breeding range (Sauer et al. 2005). These data are encouraging for the future of Yellow-breasted Chat as a breeding species in Texas. Text by Robert C. Tweit (2007)
Harrison, H. H. 1979. A field guide to western birds’ nests. Houghton Mifflin, Boston, MA.
Sauer, J. R., J. E. Hines, and J. Fallon. 2005. The North American Breeding Bird Survey, results and analysis 1966-2005. Version 6.2 2006. USGS Patuxent Wildlife Research Center, Laurel MD < http://www.mbr-pwrc.usgs.gov/bbs>
Versaw, A. E. 2004. Yellow-breasted Chat (Icteria virens). In Oklahoma breeding bird atlas, pp. 380-381 (D. L. Reinking, ed.). University of Oklahoma Press, Norman.