CHAPTER XIII 



NESTS AND EGGS, AND NESTLING BIRDS 



BIRDS, like reptiles, are egg-laying animals ; but unlike 

 reptiles, they have to brood these eggs. For the sake of safety 

 during this process of hatching the majority of species deposit 

 their eggs in some kind of a nest, and in the construction of this 

 many have acquired a most amazing skill. Some species, how- 

 ever, lay their eggs on the bare ground, as in the case of the 

 nightjar and the guillemot, for example, among British birds. 



The simplest kind of nest is that made by many of the 

 plover tribe, which find a slight hollow scraped in the ground 

 or some natural hollow all sufficient for this purpose. Generally, 

 however, this hollow is surrounded by a few stones, while some 

 species go further and interpose a few bits of dried grass 

 between the eggs and the ground. With some birds, pigeons for 

 example, a slight platform of sticks is made in the branches of 

 a tree. More elaborate are the nests of such birds as the thrushes, 

 which weave a cup-shaped nest of dried grass mixed with mud, 

 and lined with fine grass, as in the blackbird. But even 

 closely related species differ in their method of nest building, 

 as, for instance, in the case of the song-thrush, which lines the 

 nest with mud, cow-dung, and decayed wood, a mixture which 

 when dry is perfectly water-tight, so that in very wet seasons 

 the nest becomes water-logged and the eggs addled. The 

 chaffinch is a much more skilful architect, the outer walls of the 

 nest being formed of moss, spider-webs, and lichen cunningly 

 interwoven, while the lining is formed of horse-hair. 



The use of spider-webs and cotton-down and vegetable 

 matter of a like nature, for the sake of forming a kind of felt, 

 has been adopted by many species of the smaller birds all over 

 the world ; and the employment of spider-webs for attaching 

 lichen to the outer face of the nest is a device which has similarly 



