YELLOW-BILLED MAGPIE 135 



California: 30 records, April 9 to May 13; 16 records, April 14 to 

 May 6, indicating the height of the season. 



Colorado: 80 records, March 26 to May 29; 40 records, April 24 to 

 May 8. 



Montana : 17 records, March 28 to May 23 ; 8 records, May 6 to 12. 



Washington: 20 records, April 1 to May 15 ; 10 records, April 7 to 19. 



PICA NUTTAIXn (Audubon) 



YELLOW-BILLED MAGPIE 



Plate 26 



Contributed by Jean Myron Linsdale 



HABITS 



California contains within its borders the whole range of the yellow- 

 billed magpie. Localities occupied are known with exhaustive detail. 

 They are restricted to that part of the State west of the Sierra Nevada 

 from Shasta County, at the north end of the Sacramento Valley, south- 

 ward to Ventura and Kern Counties, and are chiefly in the Sacramento 

 and San Joaquin Valleys and the coastal valleys south of San Fran- 

 cisco. The area occupied is less than 150 miles wide and extends for 

 about 500 miles from north to south. 



The yellow-billed magpie is obviously a close relative of the black- 

 billed magpie. Some persons like to think of this relationship as sub- 

 specific; others consider the two kinds as distinct species. Probably 

 it makes little difference which way we think of them so long as we 

 recognize the nature of the characters and ranges of the birds, insofar 

 as they represent the true relationship, for it is scarcely possible to prove 

 the correctness of either opinion. The most nearly obvious distinctions 

 have to do with the possession of the yellow pigment, which shows in the 

 bill, claws, and some places in the skin of the yellow-billed form, and its 

 generally smaller size. Some differences in habits also may be seen on 

 close study of the two birds. The ranges do not overlap; in fact, the 

 gap separating them is about 50 miles wide at its narrowest place. 



The situation is not much different on the opposite side of the range 

 of the black-billed bird, where it approaches tlie nearest representative 

 of the group in Asia. The relationship indicated there seems even more 

 remote than that with the yellow-billed bird, but it is commonly recog- 

 nized as a subspecific one. It is true that the birds in western Europe 

 appear structurally to be much like the American black-billed ones, al- 

 though these two kinds are separated by several forms that differ con- 

 siderably from them. Somewhat similar problems arise in determining 



