National Geographic : 1932 Jul
HUMMING BIRDS, SWIFTS, AND GOATSUCKERS RIEFFER'S HUMMING BIRD (Amazilia tzacatl tzacatl) The claim of this species to inclusion in the present list is based on one captured alive at Fort Brown, Texas, in June, 1876, and brought to Dr. James C. Merrill. A careful description was taken of it, and shortly after the bird escaped. As no other specimens have been obtained, this one individual is believed to have been only a straggler. In certain lowland areas in Central America this hummer is reported as the most abundant of humming birds, ranging from the coast to an alti tude of 6,ooo feet above the sea, being a familiar species that is found regularly in cultivated re gions and about houses. It is inquisitive and active and darts here and there with shrill, chirp ing calls. In the lowlands of eastern Nicaragua, Rieffer's hummer has been found placing its nest in trees and shrubbery, but seldom at an elevation of more than six feet from the ground. Many of the nests are covered externally with moss that continues to grow in its transplanted location, so that the small, cuplike structures are handsomely deco rated in green. The female is so closely similar to the male as not always to be distinguished, but usually has the white markings of the undersurface more ex tensive, the abdomen paler gray, and the brown streak in front of the eye less distinct. This species ranges regularly from Tamaulipas south through eastern Mexico and Central Amer ica to Colombia and Venezuela. BUFF-BELLIED HUMMING BIRD (Amazilia yucatanensis chalconota) The buff-bellied hummer is plainer and less decorative in color than our other species. It is found among dense, tangled thickets, where it darts about with ease, coming out frequently into open gardens and among the bushes of pastures, where it is more easily observed. Its shrill notes often advertise its presence and call attention to birds that otherwise would be overlooked. This is another hummer, with its range mainly in Mexico, that barely crosses our borders. In the lower Rio Grande Valley, in Texas, it is com mon during the summer, arriving from the south about the first of April and remaining until Sep tember and October. These birds nest usually in open woodland and at the borders of chaparral thickets, placing their nests on small, drooping limbs or on the fork of a horizontal twig from three to eight feet from the ground. Their tiny homes are compactly and neatly built of shreds of vegetable fiber, covered externally with bits of dried flower heads, lichens, and fragments of bark and lined with thistle down. The two eggs are rather small for the size of the parent. It is believed that two broods may be reared each season. The buff-bellied hummer has a more restricted range than the majority of the species under dis cussion in these pages, being found from the lower Rio Grande Valley, in Texas, south into southern Tamaulipas and Nuevo Leon. In win ter it is reported to go as far south as southern Vera Cruz. BLUE-THROATED HUMMER (Lam pornis clemenciae) The blue-throat is one of the larger forms of its family that inhabits narrow canyons and moun tain valleys, occurring to the tops of the small mountain ranges, where it is found in the United States, and in the higher mountains of Mexico being reported to elevations of 12,000 feet above sea level. While having a swift, bulletlike flight, like many other hummers of similar size, it is quieter than some of the smaller species, resting for long periods on low, open perches on dead twigs or on the tips of maguey leaves. The birds utter sharp, squeaking calls, and the male has a simple song of three or four notes, repeated at short intervals while the singer perches upright with head elevated. Few nests of this species have been recorded. One, obtained by E. W. Nelson on the volcano of Toluca, was placed on a fork in a small shrub growing on the face of a cliff. In Arizona nests have been found inside small buildings, placed in the crook of a suspended lard pail handle or on a loop of wire. Others are reported built in an old black phoebe's nest, and among ferns. Two geographic races of this interesting spe cies are known-the Texas blue-throat (Lain pornis clemenciae clcmenciae), ranging from the Chisos Mountains, in western Texas, south to Michoacan and Oaxaca, in Mexico, and the Ari zona blue-throat (ILamipornis clemenciae besso philus), found in the Santa Catalina, Huachuca, Chiricahua, and Santa Rita Mountains of south ern Arizona, the San Luis Mountains of southern New Mexico, and the Sierra Madre of Mexico. The Arizona form differs from that of Texas in having the bill slightly shorter and the coloration somewhat duller. RIVOLI HUMMING BIRD (Eugenes fulgens) In addition to its handsome coloration, the Rivoli hummer is noteworthy for being one of the largest of its family in the United States, as it is from four and one-half to more than five inches long, with proportionately heavy body. It is found in open pine forests, where it feeds at flowers that happen to be in season. The flight is rapid, but differs from that of smaller hum mers in having an apparently less rapid wing motion, resembling to some extent that of a swift. The nest has been found among pines, fifty feet from the ground, saddled on a small limb in a location difficult of access. It is described as built of plant downs, with an external covering of lichens held in place with spider web, the structure being similar in appearance to that of the ruby-throat but considerably larger, as it measures more than two inches across. The first sight of this species is not likely to be forgotten, as among its small fellows it appears a veritable giant, with handsome coloring enhanced by its size. It is one of the most attractive birds of a region noted for interesting species. The Rivoli humming bird is found in the United States in the mountains of southeastern Arizona and southwestern New Mexico, ranging from 6,ooo to 10,000 feet altitude. To the south it occurs through Mexico and Central America to Nicaragua.