346 



A VES— SUB-ORDER CYPSELI. 



the humerus is very short, the forearm longer, and the manus extremely long, 

 in the swallows the relative proportions are exactly the contrary. 



Mr. Ernst Hartert, the latest exponent of the Cypseli, divides the single 

 family which the sub-order contains, the Cypselidce, into three sub-families, 

 CypselincR or true swifts, Chcetntiuce or spine-tailed swifts, and crested swifts 

 (Macropterygincn). From the recent researches of Mr. F. A. Lucas, it seems 

 that the last-named birds are very distinct from the true swifts, and prob- 

 ably constitute a distinct family, their singular mode of nidification, m. 

 the placing of their egg in a diminutive nest on a branch or a stump, being 

 very similar to that observed in the frogmouths (Podargi) and the Nyctibiina 

 {antea, p. 344). Mr. Hartert characterises the sub-family Cypselince, which 

 contains the true swifts, by the form of their toes, the outer and middle 

 toes having only three phalanges, while the metatarsus is distinctly feathered. 

 In one species, the pied swift of Central America (Aeronautes melanoleums), 

 the toes are also covered with plumes. The genus Micropus, of which our 

 common swift {M. apus) is the type, has all the toes directed forward, but 

 in the palm swifts (Tachorids and Claudia) the toes are arranged in 

 pairs. 



The common swift is migratory, like most of the family, arriving in Europe 

 early in May, and being one of the first of our summer birds to disappear to 

 its winter quartei-s in Africa. The mode of flight in a swift is more hke that 

 of a bat than that of a bird, especially in the gloaming, 

 when the swifts chase each other at an incredible 

 speed, uttering shrill screams. The rapidity of their 

 flight far exceeds that of any swallow. About sixteen 

 species of the genus Micropus are known. 



The sub-family Chceivrino! consists of the spine- 

 tailed swifts and the edible swiftlets. In these birds 

 the toes are normal, and the metatarsus is not 

 feathered. The spine-tailed swifts {Chmturaj are 

 found in both hemispheres, and have the shafts of 

 the tail-feathers produced into a point or spine. Some 

 of them are birds of considerable size, the needle- 

 tailed swift {Ghadura cavdacutu), which has occasion- 

 ally been seen in England, measuring nearly a foot 

 in length to the end of its long wings, which in 

 this group of swifts always protrude beyond the tail. 

 It nests in Siberia, and migrates to Australia in the winter. 



The swifts of the genus (JoUocalia are tiny birds, which inhabit the Indian 



and Australian regions. Some fourteen species are known. The birds build 



in caves, aflixing, to the walls of the limestone, cup-shaped 



nests, which are formed principally of the bird's own saliva, 



though in some species there is some moss mixed up in the 



nests, while others are almost entirely made of moss. These 



" moss " nests, however, are of no commercial value, while 



the puiie wliite nests are sold for making soup to the Chinese. 



The tree-swifts are beautiful birds, often ornamented with a large crest or 



with long white whiskers. They have the metatarsus bare, and it is shorter 



than the middle toe, whereas in tho Chatviinni the tarsus is as long as the 



middle toe, or even longer, and there are two foramina in the hinder margin 



of the sternum, whereas in the other sub-families of swifts there are no 



such notches. There is but a single genus, Maavptcnjx; with five species, 



Fig. 79. — The Common 

 HwiFT {Micropus apus). 



The Edible 



Swiftlets. — 

 Genus 



CoUocalia, 



