Tyrannus crassirostris
A casual or accidental visitor to Texas, the Thick-billed Kingbird fortuitously nested successfully in Cottonwood Campground in Big Bend National Park in the summers of 1988-1991, during the TBBA fieldwork period (Lockwood and Freeman 2004).
Thick-billed Kingbirds lack yellow on the underparts, are large and have heavy bills, separating them visually from other kingbirds in the southwestern United States.Their vocalizations are also distinctive.
Little is known about most aspects of the life history of Thick-billed Kingbird and much more study is needed (Lowther 2002).
DISTRIBUTION. Almost all of the 15 Texas records of Thick-billed Kingbird are from Big Bend National Park (Lockwood and Freeman 2004). Outside this state, the species breeds from southern Arizona along the Pacific slope of mainland Mexico to the Isthmus of Tehuantepec. In winter breeders from Arizona and Sonora, Mexico, move south. The winter range extends south into Chiapas (Howell and Webb 1995, Lowther 2002).
SEASONAL OCCURRENCE. In Arizona where most breeding in the United States occurs, Thick-billed Kingbirds arrive between mid-April and early May. Nests with young were found from June 29 to August 29. Thepair from this last date was found tending fledglings in the second week of September. Most Thick-billed Kingbirds move south from Arizona by mid-September with occasional sightings to early October (Corman 2005).
BREEDING HABITAT.In the United States Thick-billed Kingbird nests are usually found between 1050 and 1250 m (3500-4200 ft) although nests have been found as low as 600 m (2000 ft).They are often placed high in the canopy of large riparian trees. A mistletoe clump is a favorite site for the thin nest of twigs and grass. Clutches usually range from 3-5 eggs. The lengths of the incubation and nestling periods are unknown (Harrison 1979, Lowther 2002, Corman 2005).
STATUS. The Breeding Bird Survey does not provide any information on this species which has a very limited range in the United States. Corman (2005) suggests that the population in Arizona is stable or slowly expanding. If Thick-billed Kingbirds are expanding their range north from Mexico, they might again breed in Texas.
Text by Robert C. Tweit (2005)
Literature cited.
Corman, T. E. 2005. Thick-billed Kingbird (Tyrannus crassirostris), pp. 330-331 in Arizona breeding bird atlas (T. E. Corman and C. Wise-Gervais). University of New Mexico Press, Albuquerque.
Harrison, H. H. 1979. A field guide to western birds’ nests. Houghton Mifflin, Boston, MA.Howell, S. N. G. and S. Webb. 1995. A guide to the birds of Mexico and northern Central America. Oxford University Press, New York.
Lockwood, M. W. and B. Freeman. 2004. The TOS handbook of Texas birds. Texas A&M University Press, College Station.
Lowther, P. E. 2002. Thick-billed Kingbird (Tyrannus crassirostris). In The birds of North America, No. 604 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.