146 



This is an interesting species, swallow-like in outward appearance and 

 food-hunting habits yet structurally distinct from the Swallows. It is an 

 odd example of parallel development of widely separated characters induced 

 by similarity of requirement. Its habits have entirely changed since the 

 advent of the white man and, forsaking hollow trees, it is now practically 

 dependent upon chimneys for sites in which to build its nest. The winter 

 home of the Chimney Swift is unknown. The mystery, however, should 

 not be exaggerated, as there are numbers of Swifts in the western hemisphere 

 looking very like this one and the bird has probably been overlooked in its 

 winter quarters or confused with closely allied forms. The Swift spends 

 much time on the wing and seldom comes to rest except in a chimney or 

 hollow tree. In the autumn, before migration, great numbers gather to- 

 together and at evening seek the shelter of some ample chimney where 

 they pass the night. They may be seen just before dusk flying about in 

 complicated patterns near the chosen chimney, and as the sun sets, circling, 

 until as they throw the wings straight up over the back and drop fluttering 

 into the stack, one rapidly following another, they appear to pour in like a 

 miniature maelstrom. The birds cling to the perpendicular walls of the 

 chimney by hundreds, in masses like lumps of soot. Occasionally one with 

 insecure hold drops a few feet, loosening as it does so, others below; there 

 is a momentary flutter of wings and a small chorus of fine sharp chippings 

 until they find new holdings and settle for the night. 



SUBORDER— TROCHILI. HUMMINGBIRDS. 



These tiny, insect-like birds with brilliant flower-like coloration, 

 unbird-like flight, and wonderfully varied form, are a typically American 

 order. In a way, they occupy much the same position in the New World 

 as the Sun Birds do in the Old World, but the similarity between the two is 

 superflcial and not one of relationship. Many species are highly specialized 

 and exhibit some of the strangest forms in the bird world, including crests, 

 ruffs, fans, and muffs, exaggerated tails, long plumes, and enormous sword- 

 like and fine awl-shaped bills, but their most striking feature is the brilliant 

 metallic colorations on various parts of the body, that gleam in the sun. They 

 feed largely upon the nectar of flowers. The tongue is very long and 

 protrusive as in the Woodpeckers, with its sides curled over towards the 

 middle to form a double tube frayed into a brush-like tip which makes a 

 most eflicient organ for sucking liquids. Numbers of small insects, however, 

 are taken with the nectar and, from feeding experiments on captives, they 

 seem to be necessary to the bird's welfare. They are usually minute forms 

 taken from the flowers from which the nectar is obtained. 



Hummingbirds as a group are tropical and subtropical species and 

 increase greatly in number to the south, though one species in the east 

 ranges well to the north. 



FAMILY — THOCHILIDiE. HtTMMINGBIRDS. 



As there is only one family of Hummingbirds, represented in eastern 

 Canada by a single species, see preceding and succeeding headings for des- 

 cription. 



428. Ruby-throated Hummingbird, fr. — lb colibri A georqes rtjbis. ArchUo- 

 chus colvbris. L, 3-74. Plate XXII A. 



