254 



ALPINE SWIFT. 



down to the extreme south of Africa, where it is supposed, though 

 not yet proved, to breed. 



Mr. S. B. Wilson has described the nests in the cathedral at 

 Berne as placed on the ledge which goes round the tower about 

 four feet below the main floor ; sometimes there were three or four 

 in the space of three yards, all placed on the same beam. The struc- 

 ture itself is very shallow, and is made of dry leaves, bits of paper, 

 grass stems, fir-bark, and a few feathers; the whole being made 

 fairly solid by the mucous fluid which the bird emits. I believe that 

 the eggs are normally 2 in number, but as 3 and 4 are sometimes 

 found, perhaps two birds lay in the same nest ; the colour is dead- 

 white : average measurements i'2 by 77 in. The Rev. H. A. Mac- 

 pherson says that he noticed some green grass in many of the nests. 

 Mr. Wflson considers that the male and female take turns in the 

 duties of incubation, for as he was watching a bird on its nest 

 another suddenly dashed in under the roof and began to caress 

 it, and after both had twisted their heads about and rubbed each 

 other's cheeks with open bills, the sitting bird rolled itself off the 

 nest and vanished, while the other took its place. Only one brood 

 is reared in the season. The food consists of insects. The note is 

 louder than that of the Common Swift, and the flight is more power- 

 ful ; while the large size, browner colour and white belly are dis- 

 tinctive characters. 



Excepting a blackish patch in front of the eye, the upper parts, 

 sides of the neck, gorget, and under tail-coverts are of a nearly 

 uniform mouse-brown, with a metallic lustre on the wing- and tail- 

 feathers ; throat and belly white ; bill black ; feet yellowish-brown ; 

 length from bill to end of tail nearly 8 in. ; wing 8 '5 in. The sexes 

 are alike in plumage. In the young the feathers are slightly mar- 

 gined with greyish-white. 



The vignette below represents the breastbone and foot of the 

 Comi^ion Swift. 



