THE HUMMING-BIRDS AND SWIFTS 



(Families TrochilkUc and MicroftodkUc) 



BY A. A. ALLEN, PH.D. 



ASSISTANT PROFESSOR OF ORNITHOLOGY, CORNELL UNIVERSITY 



THE smallest bird in the world is a humming-bird. 

 It measures two and a quarter inches from the tip 

 of its bill to the tip of its tail and weighs but a 

 fraction of an ounce. It is called "The Fairy Humming- 

 bird" and is found in Cuba. All humming-birds, how- 

 ever, are not so small. Indeed, the giant humming-bird, 

 inhabiting the higher peaks of the Andes, is over eight 

 inches long and resembles a swallow. The majority of 

 the 580 species and subspecies, however, are tiny birds 

 under four inches in length. 



In addition to their 

 small size, humming- 

 birds are noted for the 

 brilliancy of their col- 

 ors. "Glittering frag- 

 ments of the rainbow," 

 Audubon has called 

 them, and, indeed, each 

 hue of the rainbow, 

 from the most delicate 

 blues and greens to the 

 most vivid reds and 

 purples, can be found 

 on some species. Some- 

 times the extremes of 

 color, in wonderful 

 combination, are found 

 on the back or breast 

 of a single bird. The 

 colors are not real pig- 

 ment, however, but are 

 caused by the refrac- 

 tion of light due to the 

 structure of the feather 

 and appear brilliant 

 only by reflected light. 

 Thus even the bright- 

 est members of the 

 family appear sombre 

 in many lights and as 

 they flit from flower to 

 flower, they alternately flash and fade. Many species 

 are curiously ornamented with elongated tufts of 

 feathers about the head or breast. Other species 

 have greatly elongated tail feathers four or five times 

 the length of the bird, and these are some times enlarged 

 at the end or racquet-shaped. Still others have dainty 

 little pantalets of fluffy white feathers about the legs. 



In spite of their great variety and the abundance and 

 the wide range of some species, humming-birds are 

 found only in the New World. They undoubtedly orig- 

 inated in the Andes of Colombia or Ecuador where the 



Photograph by A. D. DuBois 



THE RUFOUS HUMMINGBIRD FEEDING ITS YOUNG 



Young hummers are fed upon the nectar of flowers and tiny insects which are in- 

 jected jnto their throats by the probe-like bill of the mother-bird. Here the unde- 

 veloped, swift-like bill of the newly hatched young can be seen. Rufous humming- 

 birds are found in the West from California to Alaska. 



majority of species are still found, but some have spread 

 as far as Patagonia and others as far as Alaska. They 

 have never reached either Europe or Asia, however, and 

 numerous attempts to introduce them have failed. The 

 majority of species are quite local in their range, some 

 being restricted even to a single mountain top or to a 

 single valley. Again, although they are found all over 

 North and South America, they are very poorly repre- 

 sented in some regions. Thus, while 18 species have 

 been found in the United States, only one species, the 



ruby-throated hum- 

 ming-bird, occurs east 

 of the Mississippi Riv- 

 er. Some species live 

 in the dark humid for- 

 est, others in the arid 

 deserts, but the great 

 majority spend their 

 lives in the sunlit tree 

 tops or about clearings 

 in the forest wherever 

 there are flowers. 



It is from the nectar 

 of the flowers and the 

 tiny insects lurking in 

 the corollas that most 

 species derive their 

 sustenance. A few 

 pick insects from be- 

 neath the leaves and a 

 few others dart out 

 after passing insects as 

 do the flycatchers, but 

 these are exceptions. 

 Indeed, so dependent 

 are they upon flowers 

 that the bills of many 

 species have become 

 adapted to particular 

 flowers. In all species 

 the bill is probe-like 

 and the tongue tubular 

 for sucking the nectar, but in certain ones the bill has 

 become very much decurved, even sickle-shape, and in 

 others even upcurved to help them in getting the nectar 

 from flowers having pouchlike or liplike corollas. One 

 species has a bill nearly five inches long and another a 

 bill that measures scarcely quarter of an inch. Curi- 

 ously enough the two species feed at the same long 

 tubular flowers, the one taking the nectar in the legiti- 

 mate way, the other evading nature's provision for the 

 pollenization of the flowers, by drilling a hole through 

 the base of the corolla into the nectary, for it is upon the 



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