THE SWIFT. 7 



Food. — Insects taken on the wing, including diptera (Chironomidse 

 etc.), coleoptera (Philonthus, Quedius, Aphodius, Xantholinus, 

 Coccinella, Cryptophagus, Hippodamia, Meligeihes, Notiophilus, 

 Sitones, Staphylinidce, etc.), hymenoptera (Apis, etc., especially 

 drones of A. mellifica), lepidoptera (Triphcena). Also aphides and 

 cicadse. 



Distribution. — British Isles. — Summer-resident. Generally dis- 

 tributed except in north-west Scotland, where does not breed ; 

 I. Hebrides, where rarely breeds ; 0. Hebrides, Orkneys and 

 Shetlands, where does not breed but is fairly regular migrant. 

 These last must be passage-migrants. 



Migrations. — British Isles. — Early arrivals of summer-residents 

 begin fourth week April (early dates Mar. 21, 1892, Suffolk, Mar. 

 27, 1897, Somerset, April 12, 1905, Hants., April 14, 1912) ; main 

 arrival begins last three days April and merges into passage- 

 migration that takes place probably throughout country and by 

 west and east coastal routes, Great Britain and east coast Ireland, 

 and lasts until first week June and even later. Summer-residents 

 begin to move south mid-July and emigration from south coast 

 begins first week Aug. Passage-migrants begin to arrive east 

 coast end July mainly Forth to Thames ; numbers apparently 

 quite small north of Forth. Some evidence also of passage by 

 west coast route. Combined movement continues to end of Aug., 

 with frequent stragglers first half Sept. and occasional ones to 

 first week Oct. (late dates Cumberland, Oct. 9, 1909, Norfolk, Oct. 

 10, 1909, Glasgow, Oct, 13, 1918, Devon, Oct. 16, 1911, Butt of 

 Lewis (O.H.), Oct. 30, 1913, Middlesex, Oct. 31, 1912, Essex, Nov. 

 6, 1912, Salop, Nov. 2 to 9, 1912, Linlithgow, Nov. 13, 1917, Clack- 

 mannan, Nov. 14, 1914). 



Distribution. — Abroad. — Europe generally from about lat. 70° in 

 Scandinavia and Archangel in north Russia southwards, in winter 

 as far as south Africa and Madagascar. Casual Spitsbergen and 

 Iceland, Faeroes and Kolguev. Replaced by doubtful forms in 

 south Europe and north-west Africa, and by more distinct ones in 

 various parts of west, north, and middle Asia. 



Genus CHiETURA Steph. 



Ch^ettjra Stephens, Shaw's Gen. Zool, xiii, pt. n, p. 76 (1826, not later 

 than March — Type by subsequent designation, of Baird 1858, C. pelagica). 



Easily distinguishable from Apus by tail, in which the shafts 

 of the feathers are longer than the webs, and protrude like spines. 

 Toes and tarsus bare, tail in the only species occurring in British 

 Isles square, not in the least emarginated. Shafts of primaries 

 very strong, wings very long. Three toes only directed forwards. 



