330 NORTH AMERICAN FAUNA 61, FISH AND WILDLIFE SERVICE 



land herds by way of the Bristol Bay region. This is suggested 

 by Osgood (1904, p. 28) who mentions particularly the Lake 

 Clark and Lake Iliamna district as caribou country. Johnson 

 (1886, p. 65) saw them on the tundra near Nushagak in April 

 1886, and McKay had obtained specimens there in 1882. 



The field reports and conversations of Donald Stevenson, fur 

 warden in the Aleutians from 1920 to 1925, revealed great fluctua- 

 tions in the numbers of caribou on Unimak Island. In the early 

 eighties and nineties, there was much caribou hunting by sea 

 otter hunters, with the result that caribou were greatly reduced in 

 numbers about 1894. When only a few hundred remained, hunt- 

 ing decreased and, as caribou were more plentiful on the penin- 

 sula at that time, annual migrations brought an influx of new 

 stock which raised the herd to "full carrying capacity" of the 

 island by 1905. 



Stevenson said that no large migrations across Isanotski Strait 

 have taken place since 1908. A few crossed since then, in both 

 directions, but the last known crossing was made by 46 caribou 

 that passed over near St. Catherine Cove in December 1916. He 

 said that the caribou began to decline in numbers after 1908, but 

 that they had been increasing again more recently (as of 1925). 

 At that time (1925), he had made a tentative estimate of 7,000 

 to 10,000 animals. After my season's work, I accepted the lesser 

 figure as the more probable one. 



On Unimak Island, Urilia Bay seemed to be one of the favored 

 caribou habitats. On April 29, we saw more than 40 caribou on 

 the grass flats around the lagoon, and, a few days later, 51 were 

 counted from one point. During this period the caribou subsisted 

 chiefly on dead vegetation, except for Heracleum lanatum and 

 Coelopleurum gmelini, two robust plants that were just appearing 

 in green rosettes — these plants were eagerly eaten by the caribou. 



Winters often are stormy and disagreeable on Unimak, and 

 Stevenson suggested that a series of severe winters might have 

 been one cause of caribou fluctuations. In 1925, there were 

 reports of finding many dead caribou, and I found a number of 

 skeletons. In one instance, the animal (a bull) obviously had 

 died in a resting attitude. On May 8, I found a diseased yearling 

 bull that was blind in both eyes. 



As there has been public concern in recent years about the 

 increase of wolves, it is important to note that wolves were scarce 

 during the periods of decline of caribou on Unimak Island in 

 those earlier years, and at the time that so many caribou died, 

 in 1925, there were no wolves. Obviously, much additional in- 

 vestigation is necessary for an understanding of the caribou. 



