Chondrohierax uncinatus
The sound of an alarm note “an almost constant, loud, rattling call, descending in pitch” (Fleetwood and Hamilton 1967) heard from a large floodplain tree along the lower Rio Grande River in Hidalgo and Starr counties suggests the presence of a Hook-billed Kite nest. The kite, a mid-twentieth century addition to the Texas avifauna, feeds heavily on snails in the riparian habitat along the river. The kite is usually seen perched in a snag or flying low over the tree-tops, but will occasionally soar high in the air, where it almost takes a telescope to identify it. For plumage descriptions and life history details, see Howell and Webb (1995) and Brush (1999).
DISTRIBUTION. The TBBA field work in 1987-1992 indicated two or three pairs were nesting regularly in the old floodplain of the Rio Grande River between Santa Ana National Wildlife Refuge (NWR) in latilong block 26098-A3 and Falcon Dam (26099-E2).
From Texas the breeding range extends south on both coasts of mainland Mexico and Central America to Colombia. In South America, Hook-billed Kites are found west of the Andes from Colombia to south Ecuador. On the Atlantic slope kites are resident south to southern Brazil, Bolivia and northern Argentina. These kites are also resident in Cuba, Trinidad and Grenada (Howell and Webb 1995, Am. Ornithol. Union 1998).
SEASONAL OCCURRENCE. Hook-hilled Kite is a permanent resident along the Rio Grande River in Hidalgo and Starr counties. It is most easily seen in fall and winter; during the nesting season (April-June) it is quite difficult to see.
BREEDING HABITAT. The Hook-billed Kite, in most of its range, prefers swamps with mature trees and places its stick nest in a crotch or on a heavy limb well out from the trunk high up in a tree. The usual clutch is 2 buffy white eggs, marked with dark reddish-browns (Stiles and Skutch 1989, Howell and Webb 1995).
STATUS. Apparently the status of the Hook- billed Kite is improving in south Texas. This hawk was considered accidental by Oberholser (1974) after an unsuccessful nesting attempt in Santa Ana NWR in 1964 (Fleetwood and Hamilton 1967). A successful nesting followed at Santa Ana in May 1976 (Delnicki 1978)
Acquisition of land along the Rio Grande River by the Lower Rio Grande Valley NWR has protected nesting habitat. Early in the twenty-first century the species is considered a rare to locally uncommon permanent resident of Hidalgo and Starr counties (Lockwood and Freeman 2004).
Text by Dick D. Heller, Jr. (Posted with updates 2005).
Literature cited.
American Ornithologists’ Union 1998. checklist of North American birds, 7th ed. Am. Ornithol. Union, Washington, DC.
Brush, T. 1999. The Hook-billed Kite, a reclusive, snail-eating raptor of the Lower Rio Grande Valley. Texas Birds 1 (2: 26-32.
Delnicki, D. 1978. Second occurrence and first successful nesting of the Hook-billed Kite in the United States. Auk 95: 427.
Fleetwood, R. E. and J. L. Hamilton. 1967. Occurrence and nesting of the Hook-billed Kite (Chondrohierax uncinatus) in Texas. Auk 84: 598-601.
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, Vol. 1. University of Texas Press, Austin.
Stiles, F. G. and A. F. Skutch. 1989. A guide to the birds of Costa Rica. Cornell University Press, Ithaca, NY.