ALPINE SWIFT. 301 
again met with an accessible nest. Indeed this was the only instance in 
which we observed C. melba breeding not in large colonies.” 
The eggs of the Alpine Swift are deposited late in May, and are usually 
two or three in number, but it is said that four or even five sometimes 
occur. ‘They are elongated, and the small end is almost as blunt as the 
large end. They are pure white in colour, and vary from 1°3 to 1:2 inch 
in length, and from ‘8 to ‘72 inch in breadth. The eggs of this bird 
occasionally have more gloss on them than is usual with those of the 
Common Swift; but, as a rule, they are without polish. Their size easily 
prevents them being confused with those of the Common Swift. 
The young are fed assiduously by their parents. The food is collected 
in a mass in the mouth, so that a considerable amount is obtained ere the 
old birds convey it to their young; and it is said they thus collect all their 
food into a little round ball before swallowing it. The young are some- 
times fed on the wing by their parents. Like other Swifts and Swallows, 
the present species is much infested by parasites. The Alpine Swift. only 
breeds once in the year, and disappears from its European haunts during 
September. It passes Gibraltar on migration from late in August to 
early in October; but has been sometimes met with there as late as 
November and as early as February. 
The male Alpine Swift in breeding-plumage has the general colour of 
the upper parts, the flanks, the under tail-coverts, and a broad band 
across the breast hair-brown, the feathers of the upper parts having a 
faint purplish tinge, especially on the back and tail. The throat and belly 
are pure white; and the lores very dark brown, almost black. Most of 
the brown feathers have indistinct narrow pale margins. Bill black; feet 
and claws black ; irides dark brown. The female does not differ in colour 
from the male. Birds of the year are similar to their parents; but the 
feathers have more conspicuous pale margins, and the pale feathers of the 
underparts have dark shaft-lines. Nestlings are said to be covered with 
grey down. After the autumn moult the colour of the plumage is much 
darker and richer, and the pale margins are more conspicuous ; and after 
the spring moult there is more iridescent gloss on the feathers. The ex- 
tent to which this species sometimes bleaches during the summer is most 
remarkable. I have an example from Switzerland in which most of the 
dark parts of the plumage are the colour of sand and extremely abraded ; 
many of the feathers of the underparts have already been changed, and 
the wing-coverts are apparently just commencing to be so. The autumn 
moult has usually only just begun when the birds leave us, but the spring 
moult is completed before they again arrive in Europe. The Alpine 
Swift is subject, ike most: other birds, to the same climatic variation 
of colour which is found in the Common Swift, some examples from arid 
localities being very pale. 
