130 University of California Publications in Zoology [Vol. 12 



the Senator Mine Basin. It was doubtless in the limited tract of 

 saguaros here that Brown (1904. p. 16) found the species nesting on 

 May 17, 1903, and secured two sets of four eggs each. We noted the 

 old scars on the largest cactuses where holes had been chopped into, 

 years before our visit. Brown's was the first authentic record of the 

 elf owl for California. But Cooper found the species on the Arizona 

 side of the river, near Fort Mohave, whence on April 26, 1861, he 

 secured the type, now in the National Museum, though at one time 

 the property of the State of California (see Cooper, 1870, p. 443). 



Geococcyx calif ornianus (Lesson) 

 Roadrunner 



Safely to be considered a common resident of the whole region 

 traversed. Noted at every collecting station on either side of the river, 

 from Needles to Pilot Knob. Noted with equal frequency on the 

 upland mesas and hills, and on the first bottom even to the water's 

 edge. The peculiar notes were on several occasions heard from oppo- 

 site shores as we floated along, as though birds were answering one 

 another from across the water. 



Two examples came into our possession through being caught in 

 meat-baited steel traps set for carnivorous mammals. The stomach of 

 a roadrunner obtained at Needles contained remains of beetles and 

 one half-grown lizard (Cnemidophorus) . 



The five specimens secured by us (nos. 12705-12709). and another 

 (no. 4369) taken by J. G. Cooper at Fort Mohave, March 26, 1861, 

 give a uniform impression at first glance of paleness, as compared with 

 roadrunners from the Pacific slopes of southern and central California. 

 This paleness consists in an apparent greater average extent of white 

 markings and particularly in the whitening of the buffy lower surface 

 and a paling of the buffy margins of the dorsal feathers. The Pacific 

 slope series, however, includes specimens taken at all seasons of the 

 year, and it becomes apparent at once that the deepest buffy specimens 

 in it are those in the freshest (that is, fall) plumage. The variation 

 in the Pacific series in this respect is great, and leads to the conclusion 

 that the paleness of the buffy tints of the Colorado desert series, 

 which are February to May examples, is not altogether intrinsic, but 



