Amazilia yucatanensis
The Buff-bellied Hummingbird is one of the largest hummingbirds present in the United States, and one of three representatives of the genus Amazilia that occur north of Mexico. The primary distribution of this species is along the Gulf Coast of Mexico from Tamaulipas to the Yucatan Peninsula, into Belize, and Guatemala. In the United States this species breeds only in Texas. It has been reported in Louisiana, Alabama and Florida during fall and winter months. While the species has three recognized subspecies, the only one confirmed in Texas is A. y. chalconota (Chavez-Ramirez and Moreno-Valdez 1999).
DISTRIBUTION In Texas data collected for the TBBA indicate that Buff-bellied Hummingbirds breed only in the southern portion of the state; only 3 nesting records have been confirmed. During the spring and summer months this species is locally common at several areas of coastal and south Texas, regularly visiting hummingbird feeders and flowers in several urban areas (Kingsville, Corpus Christi, Rockport) and National Wildlife Refuges (Aransas, Laguna Atascosa and Santa Ana). Probably Buff-bellies are breeding more commonly than the paucity of nests located in the state indicates. In Texas, vagrant individuals have been recorded along the eastern edge of the Edwards Plateau, along the coast to the Louisiana border, north to Austin and Travis counties and as far west as Midland (Oberholser 1974. Lockwood and Freeman 2004).
SEASONAL OCCURRENCE: The Buff- Bellied Hummingbird shows what appears to be a unique northern movement during the fall and winter months. It is observed most commonly from March through July and August in southern and coastal Texas, ,but then becomes rare and uncommon during the fall and winter months. It appears individuals wander northward in late summer and fall after breeding. During fall and winter the species is a regular but rare visitor, on the Gulf Coast east as far as Florida.
The timing and length of the Buff-bellied Hummingbird breeding season are not well established, due to lack of confirmed records, but its presence in many areas of southern coastal Texas suggests the breeding season may extend from March through August. The confirmed nesting records from TBBA (3) are dated April through July. Bent (1940) reported 30 egg records dating between March 24 and July 16. In eastern Mexico, the breeding season is reported to be between April and July (Howell and Webb 1995).
BREEDING HABITAT: The Buff-bellied Hummingbird inhabits a variety of habitats from open woodlands to gardens. Most commonly, however, this species is found in dense thickets and brushy areas of the arid and semiarid regions of south Texas, such as oak islands. Little information is available regarding the specific nesting location of Buff-bellied Hummingbirds in Texas for recent years. The best information regarding nests has been collected from birds in Tamaulipas, Mexico. Nests have been located in small trees or bushes between 1-3 m (3-10 ft) high on forks of horizontal branches (Bendire 1895, Sutton and Burleigh 1940, Sutton and Pettingill 1942) Plant species previously reported to be used for nesting by Buff-bellied Hummingbirds include anachuita, ebony, hackberry, and occasionally willows. .
The nests of this species characteristically measure 40 mm (1.7 in) wide by 32 mm (1.3 in) deep and the cup is 22 mm (0.9 in) wide and 16 mm (0.6 in) deep. The nests are composed of shreds of bark, grass, and other vegetation fibers held by spider webs and covered on the outside with shreds of bark, lichens, and flower blossoms. While double brooding has not been confirmed, the possibility has been suggested (Bendire 1895). In northern Tamaulipas, 2 broods were observed in the same tree, one pair of fledglings were observed in early July and a second one in August, both broods are believed to be from the same nest (A. Moreno pers. comm.).
STATUS: There is little quantitative information available to evaluate the current status of the Buff-bellied Hummingbird in Texas. Oberholser (1974) expressed concern with the effect that habitat destruction occurring between 1951 and the early 1970s had on this species. Large areas were cleared resulting in the elimination of large portions of habitat used by this hummingbird.
Fortunately by the early 21st century the outlook seems brighter. Lockwood and Freeman (2004) consider the species an uncommon to locally common summer resident in the lower Rio Grande valley and along the coast north to Victoria County. The species appears to be expanding its range in Texas.
Text by Felipe Chavez-Ramirez (Posted with upfates 2006)
Literature cited.
Bent, A.C. 1940. Life histories of North American cuckoos, goatsuckers, hummingbirds, and their allies. Vol. II. Dover Publications, New York,.
Bendire, C. E. 1895. Life histories of North American birds. U.S. Nat. Mus. Spec. Bull. 3.
Chavez-Ramirez, F. and A. Moreno-Valdez. 1999.Buff-bellied Hummingbird (Amazilia yucatanensis). In The birds of North America, No. 388 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
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.
Sutton, G. M., and T. D. Burleigh. 1940. Birds of Valles, San Luis Potosi, Mexico. Condor 42: 259-262.
Sutton, G. M., and O. S. Pettingill. 1942. Birds of the Gomez Farias region, Southwestern Tamaulipas. Auk 59: 1-34.