254 CALIFORNIA BIRD STUDIES 



as the Sage Hen and American Magpie. On the western 

 boundary of the state, an extended coast-line adds a large 

 number of aquatic species to its list of birds, many of which 

 find suitable nesting places on the numerous islands off the 

 coast. 



California, therefore, has not only been given an unus- 

 ually large share of the world's assets in bird-life, but she 

 has made the most of her resources. In the absence of gla- 

 ciers, except at high altitudes, the climate of the state has 

 not suffered those changes which have so profoundly affect- 

 ed the fauna of the once ice-covered areas farther east. The 

 most distinct, and' possibly therefore some of the oldest 

 types of American land birds still exist in California. The 

 Wren-Tit, for example, which is practically restricted to the 

 state, is the only North xAmerican bird for which an inde- 

 pendent family has been suggested. Furthermore, in addi- 

 tion to the preservation of these older types, California has 

 made birds of her own. In no other part of America, possi- 

 bly in no other part of the world, have widely varying cli- 

 matic influences, aided by sharply defined physiographic 

 areas, so strongly impressed themselves on a fauna. East of 

 the Rockies, where comparatively uniform conditions pre- 

 vail, there is, for example, only one well-marked form of the 

 Song Sparrow ; but in California there are fourteen. Non- 

 migratory, and inhabiting alike dry and moist regions, 

 plains and mountains, marshes and outlying islands, the 

 species readily responds to these strikingly different envir- 

 onments. This is only one case among many, not alone with 

 birds, but with lower as well as higher types of life, and eth- 

 nologists tell us that more linguistic stocks have been devel- 

 oped among the Indians of California, than in all the rest of 

 the country. 



Broadly speaking, the leading physiographic areas of 

 California, from east to west, are the eastern desert, the 

 Sierras, the interior valley, the coastal mountains and the 

 coast. 



