This conspicuous, brightly colored kingbird was first discovered by Lieutenant Darius N. Couch in 1853, near the tiny village of San Diego, Nuevo Leon, in northeastern Mexico ( Baird 1859 , Conant 1968 ). It is now known to reside in a large area of southern Texas, north almost to San Antonio, and south along the eastern coastal plain of Mexico, throughout the Yucatán Peninsula, and in northern Central America.
After originally being described as a new species in 1859, Couch's Kingbird was reclassified as a subspecies of the Tropical Kingbird (T. melancholicus) 15 years later ( Coues 1873a ). Sennett ( Sennett 1878 , Sennett 1879 , Sennett 1884 ) confirmed that Couch's Kingbird did occur regularly in the U.S. (lower Rio Grande valley of Texas) and described the first nest. Thereafter, the species sank into obscurity, with publications simply listing it as a subspecies of the widespread Tropical Kingbird (e.g., Friedmann 1925 ). As part of an overall study of kingbird vocalizations and behavior, Smith ( Smith 1966d ) pointed out the distinctiveness of the vocalizations of Couch's Kingbird, and Traylor ( Traylor 1979e ) reclassified it as a valid species. Although there has been a modest increase in interest, the changing taxonomic status of this species has caused some confusion in the literature ( Smith 1966d , Stouffer and Chesser 1998 ). Detailed studies of individual movements, breeding biology, foraging behavior, diet, and ecology are lacking.
Couch's Kingbird overlaps extensively with the Tropical Kingbird in geographic range outside the U.S., but the former usually occupies areas with denser woody growth and can easily be distinguished by voice. Couch's Kingbird shares its south Texas breeding range with Western Kingbird (T. verticalis), which prefers more open agricultural and suburban habitats. A rejector of Bronzed Cowbird (Molothrus aeneus) eggs, Couch's Kingbird is parasitized only rarely ( Carter 1986 ). Couch's Kingbird aggressively chases Bronzed Cowbirds and potential nest predators such as Great-tailed Grackles (Quiscalus mexicanus) from the area around its nest. Such habits may partially explain both the species' success in colonizing maturing residential areas in southern Texas and its northern expansion.