370 BULLETIN 170, UNITED STATES NATIONAL MUSEUM 



night, but the greatest flights are by night. They follow the coast line, as a rule. 

 In January of this year I saw over a hundred birds in one evening from seven 

 o'clock to 10.30 P. M. 



Almost every year there is a noticeable migration of snowy owls 

 into the southern Provinces of Canada during the late fall and winter. 

 And at more or less regular intervals there have been heavy flights, or 

 invasions, of these birds into southern Canada and the United States. 

 These great flights probably occurred during periods of food scarcity 

 in the north. The principal heavy invasions were recorded during the 

 winters of 1876-77, 1882-83, 1889-90, 1892-93, 1896-97, 1901-02, 

 1905-06, 1917-18, 1926-27, and 1930-31. The big flights occurred 

 at intervals of four or five years, or multiples thereof, which probably 

 coincide with the periodic fluctuations in the abundance of lemmings 

 and Arctic hares. Considerable has been published on many of these 

 flights, giving data on the localities invaded and the large number of 

 birds recorded, based mainly on the records of taxidermists, who 

 skinned, or mounted, a large proportion of the owls captured; but 

 these figures represent, of course, only a small part of the total migra- 

 tion. Space will not permit recording here more than a few facts re- 

 garding some of the more important flights. 



The migration of 1876-77 seems to have been confined mainly to 

 the eastern part of the country, but during the winter of 1889-90, ac- 

 cording to E. S. Cameron (1907), a taxidermist in Mandan, N. Dak., 

 "had five hundred sent to him for preservation." The flight in 1901- 

 02 was recorded as far west as Michigan; and J. H. Fleming (1902) 

 estimated that somewhere between 500 and 1,000 snowy owls were 

 killed in Ontario that winter. 



The big flight of 1905-06, one of the most extensive, was fully re- 

 corded by Euthven Deane (1906); he gathered data regarding it from 

 the wide range that it covered, which included all the eastern Provinces 

 of Canada, from Nova Scotia to Manitoba, all six New England States, 

 New York, Pennsylvania, Ohio, Michigan, Wisconsin, Minnesota, 

 South Dakota, Nebraska, Iowa, Missouri, Indiana, and Illinois. Mr. 

 Deane received, during that winter, records of some 800 specimens 

 taken, showing that the flight had been quite general throughout the 

 above region. 



The winter of 1926-27 saw what was probably the most extensive 

 and the heaviest flight of snowy owls of which we have any record. 

 It extended as far west as North Dakota and as far south as North 

 Carolina. Dr. Alfred O. Gross (1927), who published a full account of 

 it, "received 2,363 records of Snowy Owls within the borders of the 

 United States", the largest numbers being recorded from Michigan 

 (592) and Maine (589), while only one each was reported from North 

 Dakota, Illinois, and West Virginia. During this flight, and at other 

 times, snowy owls have wandered far out to sea and have alighted on 



