NESTS AND EGGS, AND NESTLING BIRDS 103 



value, the combination of dark and light stripes giving a blurred 

 image, thereby rendering the individuals so marked invisible 

 at a short distance, and hence concealing them from their 

 enemies (see also pp. 65, 66). 



Where the young are hatched in a helpless condition they 

 are generally naked, or at most have but a few weak down-tufts 

 along the upper surface of the body, and insufficient to form a 

 covering. Young sparrows and young crows are absolutely 

 naked ; young thrushes generally have a few weak down-tufts 

 on the head and shoulders. 



Another peculiarity of these young birds, and indeed of the 

 young of all the Passerine or " perching-birds," is found in the 

 development of broad, fleshy folds along the sides of the beak. 

 These folds, which are generally of a bright orange-yellow, increase 

 the size of the gape of the mouth, and apparently assist the parent 

 bird when placing food in the mouth. In the picture of the young 

 starlings (p. 84) some indication of these fleshy folds remains, 

 but they speedily disappear on the development of the feathers. 

 In many young Passerine birds the roof of the mouth and the 

 tongue are spotted with black, and these spots are made more 

 conspicuous because set on a bright yellow or red background ; 

 or they may be white on a black background. 



The accompanying photographs of the young owl (p. 80) and 

 young sparrow-hawks (p. 102) well illustrate the gradual way in 

 which the down is displaced by the feathers. 



The young of birds which run about almost from the moment 

 they are hatched are generally capable of feeding themselves 

 under the guidance of their parents. But in some cases the day 

 is spent in haunts remote from the feeding ground, which is 

 resorted to at dusk. This distance being too great for the young 

 to travel, they are carried by their parents. Woodcock in Scotland, 

 for instance, often rest by day in high ground, and descend at night 

 to low swampy districts where alone they can feed. In such cases 

 they carry the young down at night, and bear them back in the 

 morning ! 



