° i9i4 J SwARTH, California Forms of Psaltripartis. 499 



THE CALIFORNIA FORMS OF THE GENUS PSALTRI- 



PARUS} 



BY HARRY S. SWARTH. 



Plate XL. 



Introduction: Throughout the greater part of CaUfornia, 

 bush-tits are famiUar features of the bird Hfe of the state. Their 

 wide distribution, covering the Transition and Upper Sonoran 

 zones, and parts of Lower Sonoran, gives them a range over most 

 of the state, except certain of the desert regions and the boreal 

 mountain tops, while the sociable and confiding nature of the birds 

 brings them into intimate contact with all who care to cultivate 

 their acquaintance. Consequently the many interesting and curi- 

 ous aspects of the life history, at least of the California species, are 

 well known, having been observed and reported upon by \'arious 

 competent observers. 



The status and relationships of the different races of the bush-tit, 

 however, have not so far been worked out to a satisfactory conclu- 

 sion, different authorities arriving at markedly different results, 

 while none of them seems adequately to have covered the situation. 

 This condition became more and more apparent with the growth 

 of the ornithological collection of the Museum of Vertebrate Zool- 

 ogy. Series after series of bush-tits were brought in from various 

 parts of the state, taken at all seasons of the year, and presenting 

 a range of variation that apparently defied explanation b.y any 

 known facts or theories regarding the species. The specimens 

 finally brought together for the present study, howe\'er, over four 

 hundred in number, seem to be quite satisfactorily representati\'e 

 of existing conditions in the genus in the state of California, enough 

 so, I believe, to justify the publishing of the conclusions to which 

 they have assisted. 



Such a study as the present one is obviously incomplete. Al- 

 though an excellent representation of material from California is 

 available, yet the genus under consideration covers a much wider 

 range than this one state, and the scrutin\- of Californian specimens 



1 Contribution from tlie Museum of Vertebrate Zoology of the University of 

 California. 



