National Geographic : 1951 Aug
Freezing the Flight of Hummingbirds concluded that hummers might well sing at a level too highly pitched for human ears. With this in mind, we watched singing Blue throats carefully through binoculars. Move ments of the throat coincided with the singing, but now and then the sounds ceased while the throat continued to vibrate, seeming to indicate that some of the passages were pitched too high for our hearing. It would not be difficult to record this song and to analyze its characteristics in the laboratory. Dr. Alexander Wetmore once wrote in the NATIONAL GEOGRAPHIC of Rivoli's Humming bird:* "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." Rivoli's Hummingbird (Eugenes fulgens, meaning the "shining one") is mainly a Cen tral American species, ranging as far south as Nicaragua and northward through the high lands of Guatemala and Mexico. It barely crosses our southern border into the mountains of New Mexico and Arizona (page 255). In slow flight the actual wingbeats of the Rivoli's become distinguishable, not a blur, as in smaller hummingbirds. The sound of the slower wings is softer. When photo graphing the three species-Rivoli's, Blue throated, and Black-chinned-in the same location, we quickly learned to identify each by the wing sounds. Black-chin Buzzes Like a Bee The little Black-chinned Hummingbird (Archilocus alexandri), though 334 inches long as against 5 inches, looked to be half the size of the other hummers (page 257). By actual weight, he should be much less. The buzzing of the Black-chin's wings sounded like a bumblebee. When the Blue-throats appeared, the little Black-chinned became timid and hard to photograph. The smallish gorget, a purple patch between the black chin and white collar, flashes only when the light is right. The Black-chinned covers an unusually wide breeding range, from southern British Columbia and western Montana to northern Mexico and western Texas, Colorado, and New Mexico. In the Huachucas at the time of our visit, the Black-chin males fed mostly on pink thistles at the canyon mouths; while females built their second nest or fed young sters. We found many nests along stream beds and low in the sycamore trees just out of the mountains. Casualty rates for nests seemed high. For example, we found three nests within a stretch of 50 yards in lower Ramsey Canyon. We marked them down for night observation, as we wished to find out whether the male took his turn at night incubation. We never learned, for within a week we found the nests all destroyed, possibly by other hummers in search of nest-building material. Though unable to observe other Black-chin nests, we made night checks of the Blue throat twice. Both times she, not he, sat on the nest. We regretted not having the opportunity to become better acquainted with Cynanthus latirostris, the Broad-billed Hummingbird. Though this charming bird undoubtedly visits the Huachucas and probably breeds there, we saw none during our stay. We found it only at Arizona's Madera Canyon, where we ob tained a few pictures of the male (page 260). The Broad-bill is a little bird, about 3/4 inches from tip to tip. A broad, bright-pink bill distinguishes the male. He wears bluish green on his gorget, green on the upper parts of the breast, head, and back, and has white posterior underparts and a glossy blue-black tail. In the United States the rare Broad bill lives only along the border in Texas, New Mexico, and Arizona. We had hoped to photograph Costa's Hum mingbird in Arizona. Records indicated that it was not likely to occur in the Huachucas. So we spent a day in the San Pedro Valley and another in Tombstone searching for the bird, but without success. Eventually Dr. Edger ton found and photographed a fine male-in New York City! This specimen, at the Bronx Zoo, was taken in Death Valley National Monument and had lived for five years in captivity in perfect health-a record. Costa's (Calypte costae) belongs to the same genus as Anna's. The males of the two species are somewhat similar, both having colored foreheads and throats. On the Costa's the color is purple or amethyst; on the Anna's, rose red. We have now recorded all but four of the 13 hummingbird species that come regularly to this country to breed: Ruby-throated, Black-chinned, Broad-tailed, Costa's, Anna's, Allen's, Rufous, Calliope, Rivoli's, Blue throated, Buff-bellied, White-eared, and Broad-billed. Still missing are Allen's, Calliope, Buff bellied, and White-eared. These four, as well as the hundreds of kinds in Mexico, Central America, and South America, leave us plenty of scope for future operations. * See "Seeking the Smallest Feathered Creatures," by Alexander Wetmore, NATIONAL GEOGRAPHIC MAGA ZINE, July, 1932. See also "Holidays with Humming Birds," by Margaret L. Bodine, NATIONAL GEOGRAPHIC MAGAZINE, June, 1928.