ABOUT BIRDS IN GENERAL. 23 



There are also great differences in the feet of birds. 

 Those that walk much, like Blackbirds, have strong, 

 well-developed feet, while the feet of birds that spend 

 most of their time in the air, such as Swallows, are 

 small and weak. Hawks and Owls have tremen- 

 dously strong feet, which they use with great skill 

 in catching and killing their prey. Water birds have 

 webbed feet, which are used as oars in swimming. 

 The feet of perching birds are so constructed that 

 certain tendons act automatically and lock the bird to 

 his perch when sleeping. 



A bird's tail is used as a rudder in flight, and enables 

 him to steer his course with precision. Long-tailed 

 birds can change their course much more quickly and 

 gracefully than those with short tails, which generally 

 make direct flights. Some birds, like Woodpeckers 

 and Swifts, have a short stiff tail, which they use as 

 a prop. Many birds use the tail to express emotion. 

 It is twitched, wagged, spread or folded, drooped or 

 tilted up, according to the disposition of its owner. 



Birds have ears, although there is usually no indi- 

 cation of them. They open a little below and behind 

 the eyes, and are hidden by feathers. The nose of a 

 bird is a pair of nostrils opening on the bill. 



Birds are classified according to their differences 

 in structure, the greater diversities separating them 

 into the larger divisions, or orders, and the lesser 

 into the nearer relationship of families. Within 

 families there is a still closer connection called the 

 genus (plural genera). Species means the particular 

 kind of bird, as Robin, Song Sparrow. The scien- 

 tific names of birds show genus and species, and the 

 genus is placed first, as if we should write Smith, John 

 instead of John Smith. 



