174 BRITISH BIRDS. 



it also possesses a song both rich, sweet, and varied. It may be heard 

 breaking out into snatches of melody as it courses through the air, espe- 

 cially the young birds in autumn ; but it often warbles when at rest, either 

 sitting on a bare twig or a building. 



The food of the Swallow consists entirely of insects. It feeds perhaps 

 more on coleopterous insects than the Martin does a fact noticed long ago 

 by Gilbert White. In proof of this the bird is very often seen to alight in 

 fields on heaps of dung, or on turnips, where it catches little beetles ; and 

 it not unfrequently alights on the roads, and even on the fields, especially 

 in dull windy weather, to pick up these insects, which will not fly in such 

 a state of the atmosphere. Sometimes it catches an insect lying on the 

 water as it passes rapidly overhead. Gnats are very much sought after 

 by this bird, as are also crane-flies, and sometimes dragon-flies. Its 

 mouth is filled with a sticky saliva, which holds the insect when caught ; 

 and it seems that the bird does not swallow its captures until it has got 

 a mouthful. Certainly when the birds are feeding their young they do 

 not return to the nest after capturing each successive fly, but only when 

 a considerable number are collected together in a sticky mass in the 

 mouth. 



There can be little doubt that the Swallow pairs for life. Unlike so 

 many of our migratory small birds, the sexes appear to travel in company 

 (in pairs) and return each season to their old haunts. 



The nest of the Swallow is generally placed on the joist which supports 

 the rafters of a barn or other outhouse, a few inches below the tiles or 

 slates which form the roof. In this position it rests upon the horizontal 

 surface of the joist, and is a ring of mud lined with dry grass and a few 

 feathers. By far the greater number of Swallows' nests which I have 

 seen in this country have been built in this position and on this model. 

 Curiously enough, this is not the case on the continent. There the 

 Swallow generally builds against a perpendicular wall, but also only a few 

 inches below some horizontal shelf or roof; in this situation the nest is 

 in the shape of a quarter of a hollow globe of mud. To increase the 

 security of the structure it gladly avails itself of any little projection or 

 nail or peg to begin upon. But the usual nest of the Swallow on the conti- 

 nent only differs from that of the Martin in having the sides as well as 

 the front open instead of built up to the projecting shelf or roof. At the 

 railway-station at Rustchuk dozens of Swallows' and Martins' nests may 

 be seen side by side, and differing only in the manner I have described. 

 In the large building where my friend Oberamtmann Nehrkorn stall-feeds 

 his cattle, near Brunswick, the roof is supported by iron pillars, and many 

 Swallows build their nests under the heavy beams which rest upon them, 

 using the iron ring which does duty as a capital to lay the foundation mud 

 upon. The continental system approaches nearest to the habits of the 



