266 BULLETIN 196, UNITED STATES NATIONAL MUSEUM 



Egg dates. — California: 104 records, April 4 to June 29; 58 records, 

 May 2 to May 31, indicating the height of the season. 



Colorado: 9 records, May 6 to June 16. 



Oregon: 29 records, April 18 to June 29; 15 records, April 18 to 

 May 21. 



Lower California: 6 records, May 15 to June 12. 



SIALIA MEXICANA OCCIDENTALIS Townsend 



WESTERN BLUEBIRD 



HABITS 



The 1931 Check-list states that the western bluebird breeds from 

 southern British Columbia to southern California, but it may breed 

 farther north. Theed Pearse, of Courtenay, tells me that the large 

 numbers that pass through that portion of Vancouver Island indicate 

 that the breeding range extends considerably north of that point. 

 The range extends eastward to northern Idaho and western Montana. 



Samuel F. Rathbun records it in his notes as a common species 

 about Seattle, Wash., from early in spring to late in fall, and of 

 frequent occurrence during the winter. It is found in logged-off 

 sections, along highways, and about isolated farms and clearings, 

 where there are a few tall dead trees. 



In the Lassen Peak region of California, according to Grinnell, 

 Dixon, and Linsdale (1930), "in summer western bluebirds were to be 

 observed about clearings and in those places where the cover of trees 

 was sparse. Individuals and pairs when not in flight were most often 

 seen perched in the tops of dead or dead-topped trees." 



Grinnell and Storer (1924) state that, in the Yosemite region, "in 

 the spring and summer months the local Western Bluebird population 

 is confined almost entirely to the blue oak belt of the western foothills 

 and hence within the Upper Sonoran Zone. * * * In the fall 

 months, however, Western Bluebirds appear at many up-mountain 

 localities not previously tenanted by the species." 



Howard L. Cogswell writes to me: "On May 6, 1936, 1 saw one pair 

 accompanied by an immature on the oak-bordered Flintridge Golf 

 Course, near Devil's Gate Dam, Pasadena; and on June 28, 1940, I 

 saw a pair feeding half-grown young in the San Gabriel River Sanc- 

 tuary, south of El Monte, in a typical Lower Sonoran riparian associa- 

 tion, at an altitude of only 300 feet above sea level." 



Courtship. — The only information I can find on the courtship of the 

 western bluebird is contained in a short note from Theed Pearse. 

 He watched a pair mating; the male, that had been sitting beside the 

 female, mounted her; and then the female mounted the male, which 



