BIRDS 63 



5. Watch a chicken, canary, sparrow, or other bird while it is 

 eating and drinking, and describe the movements that 

 the bird makes in these acts. 



C. Organs of locomotion. 



1. What is the position of the wings when they are not in use? 



2. Note and describe the movements of the wings when the bird 



is flying. 



3. The only part of the leg that is visible in most birds is the 



foot, the upper parts being covered with feathers. 

 a. How many toes do you find pointing forward and how 



many backward? (Be sure to name the kind of bird 



on which this observation is made.) 

 h. Make a drawing to show the foot and the toes with the 



claws at the end of each. Label toes and claws. 



4. Watch several kind of birds {e.g. robins, sparrows, chickens, 



starUngs), and state whether each of these kinds of 

 birds walks or hops. 



49. What is a bird ? — Birds, like fishes, frogs, and man, 

 belong to the group of animals that have a backbone, and 

 hence are known as vertebrates. It is never difiicult, however, 

 to distinguish birds from other vertebrates, since every bird 

 has wings either developed or undeveloped (Fig. 46) and a 

 covering of feathers. Birdsy too, maintain a body temperature 

 that is higher than that of any other group of animals. 

 The temperature in man, for instance, is normally about 

 985° F., whereas no bird, so far as we know, has a tempera- 

 ture less than 100° F., and even 111° F. is known to be 

 the temperature of some of the sparrows and warblers. 

 Hence, we may define a bird, as a warm-blooded vertebrate, 

 having wings and a body covering of feathers and usually 

 able to fly. 



Even a casual examination will show that a bird has a head, 

 neck, and trunk, and two pairs of appendages, namely, the 



