Buteogallus anthracinus
To feed themselves and their young, Common Black-Hawks catch fish, frogs, crustaceans, lizards, snakes and other small vertebrates and arthropods. These may be captured on the ground or in shallow water. The hawk glides down from a perch to grab its prey in a talon. (Schnell 1994).
DISTRIBUTION. During the 1987-1992 field work seasons of the TBBA project, atlasers found almost all breeding sites for Common Black-Hawk in or close to the Trans-Pecos region. The Davis Mountains had 2 confirmed breeding sites in latilong-quad 30103-E8; 2 probable sites in 30104-F2, and 30103-E8 and 2 possible sites in 30104-F1 and F2. In the Guadalupe Mountains a possible breeding site was found in 31104-H7. There was a probable site along the Rio Grande River in 29104-H5 and a possible along the river in Big Bend National Park. (29102-B8). At the eastern edge of this region, a possible site was located in 30101-D6 with a confirmed site nearby in the Edwards Plateau region in 30101-A2. This site may be that mentioned on the Devils River by Lockwood and Freeman (2004). The final site was a possible on the lower Rio Grande River in 26099-G1.
Outside Texas, the breeding range of Common Black-Hawk extends south from northwest Arizona, southwest New Mexico and Texas along both slopes of Mexico to the Isthmus of Tehuantepec. From here breeding continues along the Atlantic slope of Middle America at low and middle elevations to the northern coast of South America east as far as French Guiana. These hawks are also resident on some Caribbean islands including Cuba and Trinidad (Howell and Webb 1995, Am. Ornithol. Union 1998)
SEASONAL OCCURRENCE. Although all Common Black-Hawks breeding in Texas appear to migrate south in winter, before 1940 some black hawks were present all year in the lower Rio Grande valley (Oberholser 1974, Lockwood and Freeman (2004). Data from Arizonan show adult migrants arriving in March and mostly departing in October (some depart in September; Schnell 1994). Atlasers in Arizona recorded breeding evidence from mid-April through July (Corman 2005), consistent with egg dates in April and May reported by Oberholser (1974).
BREEDING HABITAT. Oberholser (1974) reported breeding by Common Black-Hawks in Texas occurred in riparian areas containing cottonwoods and willows. This is consistent with Arizona where 95% of breeding was in riparian areas with cottonwoods, willows and other species (Corman 2005).
The male black hawk breaks off green, leafy twigs while flapping in the air and brings them to the female who shapes them into a shallow saucer, lined with green leaves. The female lays 1-3 eggs with irregular reddish brown blotches. The interval between eggs is usually 2 days. She incubates them for about 37-39 days, starting with laying of the first egg. Some males assist with day-time incubation. Young birds remain in the nest for 41-53 days, then remain dependent on their parents for about another 2 months (Schnell 1994).
STATUS. Oberholser (1974) reported Common Black-Hawks had nested before 1940 in the Davis Mountains and along the lower Rio Grande River. No nests were found from 1940 until 1970 when a pair was found breeding in Jeff Davis County. Lockwood and Freeman (2004) and TBBA data indicate this county is the primary breeding area for Common Black-Hawk in Texas, although it is only rare to locally uncommon. Schnell (1994) quoted estimates of 220-250 breeding pairs for the total United States population (mostly in Arizona), based on surveys in Arizona and New Mexico. This population is considered self- sustaining but highly precarious.
Text by Robert C. Tweit (2007)
Literature cited.
American Ornithologists’ Union. 1998. Checklist of North American birds, 7th ed. Am, Ornithol. Union, Washington, DC.
Corman, T. E. 2005. Common Black-Hawk (Buteogallus anthracinus). In Arizona Breeding Bird Atlas. pp. 138-139 (T. E. Corman and C. Wise-Gervais, eds.), University of New Mexico Press, Albuquerque.
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.
Oberholser, H. C. 1974. The bird life of Texas, University of Texas Press, Austin.
Schnell, J. H. 1994. Common Black-Hawk (Buteogallus anthracinus). In The Birds of North America, No. 122 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.