BIRDS 233 



Classification and identification. — The class of birds, 

 Aves, is divided into various orders, of which seventeen 

 are represented in North America. There are eight 

 hundred (approximately) different species of North Amer- 

 ican birds, but in any one locality not more than about 

 a third of these species can be found, and of these only 

 comparatively few are common or numerous. So that 

 to learn the common birds of a single locality is not a 



Fig. 190. — Western chipping sparrow, Spizella socialis arizonce. (Photo- 

 graph from life by Eliz. and Jos. Grinnell. ) 



large matter; it means getting acquainted with perhaps 

 fifty or sixty different kinds. As birds can usually 

 be readily identified by their size and shape, and the color 

 pattern of their plumage, this class is especially well 

 adapted for the beginning study of systematic zoology, 

 which concerns the identification and classification of 

 species. 



To identify the various species of birds in the locality 

 of the school it will be necessary to have some book 



