82 



ANIMAL BIOLOGY 



especially characteristic of the perching birds, 

 birds in this, the highest order, are known as 



For this reason, the 

 ' birds of passage." 



Fig. 71. — The robin. 



65. Field work on birds. — Pupils should become familiar with 

 the size, form, colors, and song of as many birds as possible, and 

 should note carefully where each kind of bird is most commonly 

 found {e.g. in marshes, trees, bushes, or on the ground). In this 

 study bird glasses or opera glasses are very useful. Books like 



1 Length of robin from tip of bill to tip of tail feathers, about 10 

 mches ; length of sparrow from tip of bill to tip of tail feathers, 

 about 6 inches. 



