Sept., 1924 



183 



FALL MIGRATION NOTES FROM THE 



SAN FRANCISCO MOUNTAIN REGION, ARIZONA 



(with two photos) 



By HARRY S. SWARTH 



(Contribution No. 424, from tlie Museum of Vertebrate Zoology of the University of California) 



DURING the fall of 1922 the present writer spent two months in field work in 

 the vicinity of San Francisco Mountain, Arizona. This work was conducted 

 in conjunction with Dr. Francis B. Sumner, of the Scripps Institution for 

 Biological Research, and his assistant, Mr. Ralph R. Huestis. The expenses of the 

 trip were defrayed in part by Mr. E. W. Scripps, through the Scripps Institution, in 

 part by Miss Annie M. Alexander, through the Museum of Vertebrate Zoology. 

 Dr. Sumner was in charge of the expedition, the main object of which was a study of 

 certain small rodents of the region explored. (See "The supposed effect of the color 

 tone of the background upon the coat color of mammals," by F. B. Sumner and 



Fig. 47. Dove Tank, near Deadman Plat; artificial storage of surface water in 

 A region with few permanent springs and streams. Photographed October 11, 

 1922. 



H. S. Swarth, Journal of Mammalogy, vol. 5, May, 1924.) Mammal collecting took 

 up all of the time of Dr. Sumner and Mr. Huestis, and a large portion of my own. 

 I did give some time to birds, however, keeping notes on all species observed, and, 

 especially in the latter part of our stay, collecting specimens of many of the species. 

 Most of the mammals and all of the birds I collected, together with field notes and 

 photographs, are in the Museum of Vertebrate Zoology. 



The following notes are presented mainly for their value as statements of 

 occurrence. Our time in the field covered most of the period in the fall when birds 

 were actively migrating, and in many cases I was able to ascertain exact dates of 

 arrival and departure. I believe there have been few observations of the sort from 

 this section. 



