414 LIFE HISTORIES OP NORTH AMERICAN BIRDS. 



Brown has repeatedly examined sahuaras out in tlie deserts without finding 

 a single Owl in any of them, although they were full of suitable excava- 

 tions. In a single instance he found one of these birds some distance away 

 from the lowlands, near the summit of the Quijotoa Range, 90 miles south- 

 west of Tucson, Arizona. 



From two to five eggs are laid to a set, but the most common number 

 found is three. Of thirty-eight sets taken by Mr. F. Stephens, who found the 

 first eggs of this species, twenty-four sets contained three each, twelve sets 

 contained four, and two sets five eggs. The cavities in which they are 

 deposited are usually about 10 inches deep. There is no nest, the eggs simply 

 lying on the dry chips in the bottom of the hole. One of the parents is 

 always at home after the first egg is laid, and frequently both. The male 

 assists in incubation, which lasts about two weeks. The eggs of the Elf 

 Owl are pure white in color and oval in shape, the shell is finely granu- 

 lated, and while some specimens are rather glossy, the majority are only 

 moderately so. 



The average measurement of twenty-three specimens in the U. S. Na- 

 tional Museum collection, all taken by Mr. E. W. Nelson, is 27 by 23 

 millimetres. The largest of these eggs measures 28.5 by 24, the smallest 

 25 by 22.5 millimetres. 



The type specimen, No. 22134, was taken by the above mentioned gen- 

 tleman near Fort Lowell, Arizona, May 25, 1884. The set contained three 

 eggs. The specimen is figured on PI. 12, Fig. 13. 



