302 BRITISH BIRDS. 
Genus CHAETURA. 
The Spine-tailed Swifts were included by Linnzeus in the genus Hirundo 
with the other Swifts and the Swallows. From the latter the Swifts were 
separated as early as 1777 by Scopoli; and in 1825 Stephens placed the. 
Spine-tailed Swifts in a new genus, which he called Chetura (Shaw’s Gen. 
Zool. xii. pt. 2, p. 76). The American Chimney-Swallow (C. pelasgia), 
the first enumerated by Stephens, has been generally accepted as the type. 
The Spine-tailed Swifts may be at once recognized by having the shafts 
of the tail-feathers prolongated like needles or spines beyond the web. 
The tail is very short, considerably less than half the length of the wing, 
and the wings are very long and powerful. Unlike the true Swifts, in the 
foot of the Spine-tailed Swifts three toes are directed forwards and one 
backwards. The plumage of the upper parts is generally glossed with 
metallic purple and green. 
Sclater (Proc. Zool. Soc. 1865, p. 607) enumerates fifteen species 
belonging to this genus, of which seven belong to the Neotropical and 
two to the Nearctic Region; three breed in the Oriental and two in the 
Ethiopian Region ; whilst one breeds in the Palearctic, wintering in the 
Australian Region. One species is an accidental visitor to Europe and 
the British Islands. 
The Spine-tailed Swifts are gregarious, chiefly frequenting open 
country, and living almost entirely on the wing. Few, if any, birds exceed 
them in the rapidity of their flight. They feed exclusively on insects. 
They breed in hollow trees, holes in rocks, or in chimneys, using no mud 
in the construction of their nests, but cementing the materials, which 
consist of straw, hay, or twigs, with their glutinous saliva. The eggs are 
few in number and dull white in colour. 
