372 



NORTH AMERICAN FAUNA. 



[NO. 27. 



Bubo virginianus subarcticus Hoy. Arctic Horned Owl. 



This species occurs rather commonly in summer throughout the 

 region north to the limit of trees. It is to some extent migratory, 

 retiring in winter from the northern portion of its range, and then 

 becoming much more abundant than in summer over the region 

 southward from Great Slave Lake. 



In the spring of 1901 the notes of great horned owls, probably 

 this form, were heard near Vermilion Creek, 40 miles north of Ed- 

 monton, May 3; on the Athabaska 60 miles below Fort McMurray, 

 May 15; and near Fort Chipewyan May 23. The species was next 

 noted on Slave River about 100 miles below Fort Smith, July 1, 

 when we saw a pair with four nearly grown young. The old birds 

 immediately flew away, but two of the young, one of which is con- 

 siderably lighter in color than the other, were obtained. While we 

 were ascending the Athabaska we saw an adult near La Biche River 

 August 27. 



In 1903 the notes of this owl were heard 50 miles north of Edmon- 

 ton on the night of May 13. One was seen sitting at the mouth of a 

 cavity in a large balsam poplar 50 miles below Athabaska Landing 

 May 17, and several were heard hooting near the outlet of Athabaska 

 Lake June 8. The species was next noted by my brother and Gary 

 on the mountain at the mouth of Xahanni River, where one was seen 

 July 14, and the notes of one were heard on the night of July 17. 

 On the return trip in the fall the species was heard nightly in the 

 hea^'y spruce woods near Athabaska Landing September 4 to 15. 

 During my trip northward from Fort Rae I saw one on Lake 

 Faber on the evening of August 6. I heard the notes of great horned 

 owls on Bear River September 29; and on the Mackenzie 20 miles 

 ^ >w Gravel River October 3 ; near Roche Trempe-l'eau October 

 8 ; and 50 miles below Fort Simpson October 16. Great horned owls 

 were common during the autumn and early winter at Fort Simpson, 

 and a large series was taken by trapping. The greater number are 

 referable to B. v. siibarcticus. Most of these are very light colored, 

 typical birds, but some are darker, inclining toward saturatus. 

 Most of these birds probably were migrants, since the species was too 

 abundant to be considered as represented only b}^ residents, and, 

 furthermore, the breeding birds taken are all referable to B. siibarcti- 

 cus. One taken ^^'ovember 21 had eaten a small shrew {Sorex fcr- 

 sonatus) ; one November 23, a red squirrel {Sciurus Jiudsoniciis) ; one 

 December 1, several meadow voles {Microtus drummoncU) , white- 

 footed mice {Pei'omyscus arcticus), and shrews {Sorex personatus) . 



During J anuary and February, 1904, 1 occasionally heard the notes 

 of great horned owls, and I heard them frequently during March. 

 On March 14 I saw a pair in the vicinity of a prospective nest in a 



