58 



THE FOOD OF ANIMALS 



plumage harmonizes most closely with surrounding tints." The 

 Whip- Poor- Will of North America {Caprimulgus Virginianus) 

 is a closely-allied species. 



Quite another sort of arrangement is presented by Wood- 

 peckers (fig. 347), in which the foot is admirably adapted for 

 climbing, having two long toes directed forwards and two others 

 backwards, all being provided with sharp claws that can take 



advantage of the smallest ir- 

 regularities on walls, the bark 

 of trees, and similar surfaces. 

 The stiff tail is also of assist- 

 ance in climbing. The power- 

 ful pointed and rather long 

 beak is suited for introduction 

 into crevices, and the mobile 

 tongue, covered at its tip with 

 backwardly - directed spines 

 and rendered sticky by the 

 secretion of large glands, is 

 an excellent insect -catching 

 organ. The arrangements 

 found in some insectivorous 

 Mammals are here once more 

 recalled. It should further 

 be added that the "hyoid 

 bone ", by which the tongue 

 is supported and to which the muscles moving it are attached, 

 is unusually well developed, and possesses slender prolongations 

 which curl round over the top of the head underneath the 

 skin. 



The Common Cuckoo (Cuculus canorus), which is related to 

 the Woodpeckers, may be mentioned in passing as an insectivorous 

 bird of great voracity, and is especially interesting as having 

 discovered a hunting-field in which little if any competition is 

 encountered. That is to say, it feeds largely upon hairy cater- 

 pillars, which other birds find extremely distasteful and never 

 touch if they can help it. 



Many of the sharp-beaked Perching Birds feed largely upon 

 insects in their various stages, as well as upon other small 

 creatures, but space forbids mention of more than a few examples. 



Fig. 347. — Greater Spotted Woodpecker [Detidrocopus viajor) 



