524 



PASSERIFORMES 



CHAP. 



Africa, Borneo, and Burma. The summer migrants to Britain are 

 Hirundo rustica, the Swallow, Chelidon urbica, the Martin, and 

 Cotile riparia, the Sand-Martin. Swallows traverse immense 

 distances on their periodical journeys, while all perhaps shift their 

 quarters to some extent for the winter. 



Hardly any sort of country comes amiss to these birds, 

 though the neighbourhood of water is preferred, and for some 



species seems necessary. 

 Spending their life chiefly 

 in the air and alighting 

 comparatively little, they 

 rapidly dart, twist, double, 

 sail aloft, or skim the 

 water's surface in com- 

 pany, at times chasing 

 each other in sport or even 

 iighting savagely. Insects, 

 which form the whole of 

 their sustenance, are ha- 

 bitually taken on the wing, 

 and the young are some- 

 times fed, or building ma- 

 terials snatched up, in full 

 flight. A few species not 

 uncommonly perch on 

 trees, as Hirundo rustica, 

 Tachycineta alhiventris,Petrochelidon nigricans, FsalidojJrocne nitens 

 and Procne tapera ; the last-named, moreover, is exceptional in 

 being non-gregarious, while it flits about with depressed wings 

 and slow butterfly-like flight when not hawking. The majority 

 are rarely seen on the ground, unless they are procuring mud for 

 nidification ; but many roost on reeds or in their nests, and just 

 before migration they settle in crowds on branches, fences, wires, 

 and ridges of roofs. Hirundo, Clielidon, and Fsalidoprocne bask in 

 the sun on gravelly places. The twitter or warble of Swallows 

 uttered on the wing or at rest and their squeaks of anger or 

 alarm, are well-known ; the scream of Procne and the chirp of 

 Stelgidopteryx being somewhat exceptional ; when excited, however, 

 the bill is not uncommonly snapped noisily. The nest may be 

 cup-shaped as in our Swallow, Cotile rupestris, C. fuligida, and 



Fig. 115. Swallow. Hirundo rustica. 



