14 OUR DOMESTIC BIRDS 



The most important function of the tail in flight is to balance 

 the bird. It is of some assistance in steering, but a bird steers 

 its course mostly by manipulation of the wings. 



Scratching. With the exception of the aquatic birds and the 

 ostrich, all the species of poultry belong to the group called by 

 naturalists Rasores or Scratchers. Birds of this class have legs 

 of moderate length and very strong, with toes terminating in a 

 stout claw. Normally they have three toes upon which the foot 

 rests when they are standing on a flat surface, and a fourth toe, 

 like a thumb, which assists the other toes to grasp a perch. Some 

 individual birds and some races of birds have the fourth or hind 

 toe double. The leg of a bird is so constructed that when it is 

 bent as the bird sits on a narrow support the toes contract and 

 grasp the support and hold it without any effort on the part of 

 the bird. Thus the bird is as secure in its position on a limb 

 when asleep as if wide awake and looking out for itself. 



In proportion to their ability to scratch, birds are able to find 

 seeds and insects concealed among dead or living vegetation on 

 the surface of the ground, and also to dig below the surface. 

 Scratching capacity is most highly developed in the fowl. Com- 

 pared to it the other land birds are very feeble scratchers, and 

 do little damage by scratching if 'free to roam about. For ages 

 the scratching propensity of fowls was regarded as a vice in 

 them, but since people began to give special attention to poultry 

 they have learned that fowls are much more contented and 

 thrifty in confinement if their food is given them in a litter of 

 leaves, straw, or shavings, in which they must scratch for it, and 

 have also found that to some extent fowls may be used to culti- 

 vate crops while destroying insects and weeds among them. 



Swimming. Capacity for swimming has an economic value 

 in domestic birds because it adapts those possessing it to places 

 which land birds rarely frequent. It will be shown when the 

 different kinds of aquatic birds are described that each has its 

 special place and use in domestication. 



