430 'PICARIAN' BIRDS 



in the latter. With the exception of being unknown in the polar 

 regions, swifts are cosmopolitan birds. 



The true, or common, swift {Micropus apns of some writers and 

 Apiis apus of others) is the typical representative of the family, and, 

 together with several allied species, is characterised by the feathering 

 of the legs extending down to the toes. In length the swift measures 

 about (j\ inches ; in colour both sexes are uniformly sooty brown, 

 with the exception of a small patch on the under surface of the lower 

 jaw, which is whitish. In young birds there is more white on the 

 throat, and the feathers have pale margins — features indicative of the 

 derivation of swifts in general from birds with a more normally coloured 

 plumage. 



The swift is a migratory bird, arriving in the British Isles not 

 before the end of April or the beginning of May, and departing as a 

 rule in August, although a few individuals, especially in the southern 

 counties of England, may occasionally linger till September or even 

 later. The great majority of swifts spend the winter in Africa ; and 

 the eastern range of the species extends to Afghanistan and Kashmir. 

 Swifts range as far north as Lapland, but do not apparently breed in 

 Scandinavia farther north than latitude 69 or thereabouts, and in the 

 Ural district only up to about latitude 60'. Like swallows, these 

 birds attain the more northern portions of their range very gradually, 

 arriving in the southern parts of Europe as early as March, and 

 advancing across the continent in a wave, so that Lapland is not 

 reached till June. A cold spring, after an interval of genial weather, 

 often plays sad havoc with swifts, many of which are not unfrequently 

 struck down by a " blizzard " in a dead or dying condition. As 

 implied by its name, the swift is a bird of extremely rapid flight, 

 although it is excelled in this respect by the larger Alpine species ; 

 and spends the greater part of the day on the wing, but is most active 

 towards evening, when it may be seen dashing high in the air round 

 church-steeples, uttering its loud screaming call. Its food consists 

 entirely of insects, which are taken on the wing. As a rule, swifts 

 seldom voluntarily alight on the ground, from which, however, they 

 are able, although with some difficulty, owing to the length of their 

 wings, to rise directl)' into the air. When retiring to roost, or for 

 purposes of nesting, the>- betake themselves to crannies in high build- 

 ings or ledges on cliffs, from which they arc able at once to precipitate 

 themselves into the air when about to resume their flight. The nest, 

 which may be either under a roof or in a cleft in a tower-wall or the 

 face of a cliff, is a poor structure of straw, grass, feathers, and wool, 



