1914] Grinnell: Mammals ami Birds of Ihr Colorado Valhij 131 



due in part at least to an extreme amount of fading. This does not, 

 however, account for the average greater extent of white areas on the 

 individual feathers of the desert birds. But this feature i.s too variable 

 in both series to be satisfactorily defined. 



It is of course a remarkable exception if the roadrunner, a ter- 

 restrial, permanently resident bird of all the areas it inhabits, .should 

 not show some geographic color peculiarities. Indeed it is all the more 

 strange that it does not show conspicuous differences in color tone 

 in the arid and subliumid areas it occupies, when we observe the 

 markedly different color tones exhibited by the thrashers, towhees, 

 spermophiles, and jack rabliits of the same areas, these being also ter- 

 restrial animals. 



The roadrunner 's failure to conform to the rule offers a problem 

 for those who would explain animal coloration wholly on the grounds 

 of physiological response to meteorological conditions, irrespective of 

 adaptive value. 



Ceryle alcyon i Linnaeus) 

 Belted Kingfisher 



Our observations would indicate tliat this species occurred oidy as 

 a migrant through the region. The first individual was noted Ai)ril 

 6 on the California side below Cibola ; another was seen on the seventh 

 on the Arizona side ten miles below Cibola. In both these cases, and also 

 subsequently, the birds were perched on .snags intently watching the 

 muddy current. But the futility of their scrutiny was apparent in 

 that at no time was a kingfisher .seen to plunge into the water in the 

 characteristic fashion of the species when capturing a fish ; the 

 opacity of the mud-laden water was mo.st certainly unfavorable to 

 this mode of securing fish. Kingfishers, but one at a time, were seen 

 April 19, eight miles east of Picacho; Jlay 3. five miles northeast of 

 Yuma ; and Jlay 5, near Pilot Knob. 



There was not the lea.st doubt in any of these instances that the 

 bird seen was the large belted kingfisher and not the little Texas green 

 kingfisher. Cones 's oftquoted statement (1866. p. 59) that he observed 

 the latter species "at several points on the Colorado River between 

 Forts JMohave and Yuma" in the autumn of 1865 remains unconfirmed 

 bv anv later observation. 



