THE GREAT HORNED OWL. 383 



ants, and as soon as their young have left it is taKen possession of by one of 

 the larger Hawks for the same purpose. Although at all other times unsocial, 

 during the season of reproduction the Great Horned Owls are generally 

 devoted and courageous in the defense of their young, caring for them long 

 after leaving the nest. Collectors have been known to be vigorously attacked 

 and even beaten off by them, and were quite willing to make a hasty retreat 

 in order to keep out of reach of their sharp and powerful talons. 



The eggs of the Great Horned Owl, usually two or three in number, are 

 white in color, and show little or no gloss, though there are occasional excep- 

 tions; they are rounded oval in shape; the shell is thick and rather coarsely 

 granulated, feeling rough to the touch. 



The average measurement of twenty-five specimens is 56 by 46.5 milli- 

 metres. The largest of these eggs measures 58.5 by 48.5, the smallest 51 by 

 44.5 millimetres. 



The type specimen, No. 20629 (PI. 12, Fig. 12), from a set of two, was 

 taken by Capt. B. F. Gross, near Pewaukee, Wisconsin, March 13, 1883. 



134. Bubo virginianus subarcticus (Hoy). 



WESTERN HORNED OWL. 



Bubo subarcticus Hoy, Proceedings Academy Natural Sciences Phila., vi, 1852, 211. 

 Bubo virginianus fi subarcticus Ridgway, Ornithology of the 40th Par., 1877, 572. 

 (B 48, part ; C 317a, part ; R 405a, part ; C 463, part ; U 375a.) 



Geographical range : Western United States (except northwest coast) ; east- 

 ward across the Great Plains, straggling to northern Illinois, Wisconsin, and western 

 Canada; north to Manitoba; south over the table-lands of Mexico (Lower California ?). 



The breeding range of the Western Horned Owl, a lighter gray and 

 buff colored bird than the preceding subspecies, extends from the Mexican 

 table-lands, north through southwestern Texas, New Mexico, Arizona, Colo- 

 rado, western Kansas, western Nebraska, Utah, Wyoming, Montana, and 

 western South and North Dakota, as well as beyond our border into western 

 Manitoba, Assiniboia, and southern Alberta. On the Pacific coast it is found 

 from (Lower? and) southern California northward through all the intervening 

 States, on both sides of the Sierra Nevada, passing through British Columbia 

 to Alaska, along the Lower Yukon River and shores of Bering Sea, to about 

 latitude 65° N. 



According to Mr. William Brewster, the Horned Owls found in Lower Cal- 

 ifornia are much smaller in size and darker colored than the Western Horned 

 Owl, resembling the Dusky Horned Owl somewhat in coloration, and they will 

 have to be separated as a new geographical race. 



The Western Horned Owl is only found in the lower foothills and more 

 open country throughout the range indicated, while in the higher mountain 

 regions, it is replaced by the Dusky Horned Owl (Bubo virginianus saturatus). 



