352 THE SWIFT 



two consecutive seasons, between the dates of arrival at two Aberdeenshire colonies 

 ten miles apart. The swift journeys both by day and by night. [A. L. T.] 



4. Nest and Eggs. The nest is generally found under the eaves of buildings 

 or in crevices and holes in walls, less frequently in natural crannies and crevices of 

 rocks and quarries. When suitable accommodation is available, it always breeds in 

 colonies. Exceptionally it has been known to take possession of a house-martin's 

 nest, and in East Prussia, Finland, and Corsica it breeds in woodpeckers' holes and 

 natural openings in trees (cf. Vertebrate Fauna of the Moray Basin, vol. ii. pp. 298-9). 

 The nest itself is of a very simple character, being merely an accumulation of straws, 

 grasses, seeds of various trees and feathers, picked up on the wing or found in 

 the nest-hole, and fastened together by a viscous secretion from the mouth of the 

 bird, apparently the work of both sexes. Fresh flowers of buttercups have also 

 been recorded several times as found in nests. The eggs are two or three in number, 

 chalky white in colour, and devoid of gloss. Average size of 100 eggs, '98 x -63 in. 

 [24'9 x 16*2 mm.]. They are laid in the last week or so of May and early in June, 

 and incubation, which lasts about 18 days, appears to be performed by the hen 

 alone. Only one brood is reared during the season. [F. c. R. J.] 



5. Food. Insects, chiefly Beetles and Flies, also Lepidoptera. The young 

 are fed on insects, almost certainly by both parents, but the evidence conflicts (see 

 p. 360). [F. B. K.] 



6. Song Period. Its song, if this term may be applied to its harsh scream- 

 ing notes, is heard during most of its stay. [F. B. K.] 



The following species are described in the supplementary chapter on " Rare 

 Birds " : 



Alpine-swift, Apus melba (L.). 

 Needletailed-swift, Chcetura caudacuta (Latham). 



