GREAT HORNED OWL 321 



The Arctic horned owl (B. v. subarcticus) (=B. v. wapacuthu (Gmelin) 

 of Oberholser and Ridgway) is found from the limit of timber in the 

 Mackenzie Valley and Hudson Bay south to northern Alberta, north- 

 ern Saskatchewan, central Manitoba, and northern Ontario. In 

 winter sometimes reaching southern British Columbia, Idaho, Ne- 

 braska, and Wisconsin. Casual in New York and Massachusetts. 



The western horned owl (B. v. pallescens) ranges from northeastern 

 California (Lassen County), Idaho, and Utah east to New Mexico and 

 central Texas and south to the Mojave Desert and the Mexican States 

 of Sonora, Durango, and Nuevo Leon. 



The dwarf horned owl (B. v. elachisius) occurs chiefly in the Cape 

 district of Baja California. 



The Pacific horned owl (B. v. paciftcus) occupies the great interior 

 valleys of California south to northern Baja California. 



The Montana horned owl (B. v. occidentalis) occurs from southeast- 

 ern Oregon, central Alberta, Montana, South Dakota, and Minnesota 

 south to Iowa, Kansas, Wyoming, and northeastern California. 



The northwestern horned owl (B. v. lagophonus) ranges from Cook 

 Inlet and the interior of Alaska south through central and eastern 

 British Columbia to northeastern Oregon and Idaho. Casual in 

 Colorado and Minnesota. 



The dusky horned owl (B. v. saturatus) is found from the coast 

 region of southeastern Alaska south to northern California. 



The St. Michael horned owl (B. v. algistus) occupies the coastal 

 regions of Alaska from Bristol Bay north to Kotzebue Sound and 

 casually Point Barrow. 



Migration. — As stated above, the horned owls are nonmigratory in 

 the sense that they do not make regular seasonal journeys between 

 breeding and wintering grounds. That they can perform flights of 

 considerable length is demonstrated by the casual records of specimens 

 of certain geographic races that have been collected at points well 

 outside their normal ranges. Such travels are, however, probably 

 caused by shortage of the food supply in the normal range of the in- 

 dividual concerned rather than by the seasonal prompting that is 

 responsible for the journeys of the truly migratory species. 



This is further exemplified by a study of banding data. The files 

 of the Biological Survey contain the recovery records of more than 40 

 banded horned owls. With few exceptions these birds were all re- 

 captured within a relatively short distance of the place where they were 

 banded, the elapsed time being from a few months to about two years. 

 In only one instance is there definite evidence of a long flight — a 

 juvenile bird banded at Rosebud, Alberta, on May 23, 1930, and 

 recovered at Antelope, Mont., on January 8, 1931. The distance 

 covered is about 220 miles. 



Egg dates. — Alaska and Mackenzie: 5 records, April 1 to May 13. 



