134 University of California Publications in Zoology [Vol. 12 



larger cactuses contained from one to four holes each. At the date 

 they were examined, March 27, egg-laying had not yet commenced. 



Where the better defined belt of saguaros meets the Colorado above 

 the Laguna Dam, with well represented tracts on both sides of the 

 river, the Gila woodpecker abounded. The availability of satisfactory 

 sites would therefore seem to be the prime factor in governing the 

 local distribution of this species. For the cactus itself certainly 

 would not seem to afford food, except during the fruiting season, or 

 other attractions. 



In this vicinity nests were found in saguaros as follows: On the 

 Arizona side, five miles above Laguna, April 24, a set of three fresh 

 eggs, twelve feet above the ground ; on the California side, four miles 

 above Potholes, April 23, nest (not investigated) twenty-four feet 

 above the ground; another nest, same place and date, fourteen feet 

 above the ground, with four small young. 



In the same vicinity Gila woodpeckers were nesting also in dead 

 cottonwoods in the river bottom. The birds appeared to find favorable 

 foraging grounds both in the riparian tracts and out on the desert. 



A series of twenty-three adult specimens was taken, nos. 12733- 

 12755. 



There are five other skins in the Museum, nos. 4330-4334, taken 

 at Fort Mohave by J. G. Cooper, December 24 and 25, 1860, and 

 February 4 and March 12, 1861. It is to be remarked that not an 

 iota of difference, save as is accountable for by extraneous causes, is 

 observable between the Cooper birds obtained fifty years ago and the 

 freshly obtained material. Considering the rather intricate color 

 pattern and the opportunity thus afforded for the detection of deter- 

 minate or any other sort of variation, this is indicative of constancy 

 of characters under natural conditions through a long series of genera- 

 tions. 



Colaptes cafer collaris Vigors 



Red-shafted Flicker 



Evidently a common winter visitant. Noted daily the third week 

 of February in the willow timber of the river bottom below Needles. 

 and early in March in the narrower willow association on both sides 

 of the river opposite The Needles ; likewise in Chemehuevis Valley. 

 The last individual of the species observed, was shot in the willows on 



