BIRD STUDIES IN CALIFORNIA 



INTRODUCTORY 



It is impossible to speak of California descriptively with- 

 out using superlatives. If not the largest state in the Union 

 it is at least the longest ; 770 miles separating its northern 

 and southern boundaries; it has the highest mountain (Mt. 

 Whitney, alt. 14,501 ft.) and the greatest depression (Sal 

 ton Sink, 287 ft. below sea level). It has a rainfall as low 

 and nearly as high, as that of any other part of the Union. 

 Owing, therefore, to its great extent, its diversified 

 topography and its extremes of temperature and of aridity 

 and humidity, California is a land of perpetual snow and 

 endless summer; of barren deserts and luxuriant forests; of 

 wide-stretching plains and majestic mountains; of expan- 

 sive marshes and bold, rocky, islet-beset coast-lines. 



In consequence of these widely varying climatic and 

 physiographic conditions, California is admirably fitted to 

 support an exceptionally rich fauna. Among birds, some 

 five hundred species and subspecies, or nearly one-half the 

 number known from America north of Mexico, have been re- 

 corded from this single state. 



However, it is not only to the favorable conditions just 

 outlined, but also to its geographical position that Califor- 

 nia owes its abounding bird-life. The mountains which enter 

 it from the north form an effective pathway for the exten- 

 sion southward of many boreal species ; while at its south- 

 ern border, both mountains and deserts have proved gate- 

 ways through which have entered species from temperate 

 as well as from tropical Mexico. 



The Great Basin, which encroaches on California 's east- 

 ern frontier, gives to it such characteristic interior species 



