296 NORTH AMERICAN FAUNA 61, FISH AND WILDLIFE SERVICE 



Kellogg (1936) found no bones of the Arctic fox in the midden 

 material from Kodiak Island, though the red fox was abundantly 

 represented. Probably this fox never ranged on the more rugged 

 Pacific side of Alaska Peninsula. 



It appears, then, that the Arctic fox, mostly in its blue color 

 phase, reached the westernmost Aleutians from the Commander 

 Islands, while the Alaskan continental form straggled out, at 

 least part way, on Alaska Peninsula. 



Food Habits 



The leasing of islands for the purpose of raising blue foxes has 

 a direct influence on the native fauna, therefore particular at- 

 tention has been given to the food habits of the blue fox in the 

 Aleutians. Accordingly, we made every effort to learn what 

 constituted the fox food on each island. This was accomplished 

 by the only two methods possible — observation and the analysis 

 of droppings. Such studies were made on about 40 islands, though 

 data from a few of these were meager. Table 1 presents the 

 food habits data obtained on 22 islands, from the contents of 

 more than 1,800 blue fox droppings. While a much greater num- 

 ber would be desirable from any given island for a complete pic- 

 ture of the food habits pattern in percentages, the data here 

 presented agree closely with our field observations and furnish 

 an accurate statement of the food that is available and utilized 

 by the blue fox in the Aleutians. 



It had been assumed by lessees operating in the Aleutians that 

 sea urchins were the most important food item, supplemented by 

 birds and beach drift. We found that sea urchins, though ac- 

 ceptable, do not rank in importance with amphipods (tiny crus- 

 taceans commonly referred to as beach fleas). Crustaceans were 

 found in 26.1 percent of the droppings studied, and sea urchins 

 were found in 2.1 percent (see table 2). 



Beach fleas appear to be the most commonly available food 

 item. They swarm on the beaches, where windrows of dead kelp 

 furnish a favorite habitat. They lurk under bits of wood, or 

 under anything else that may lie on the sand and preserve the 

 required moist shelter underneath. It is easy for a fox to pick 

 up a full meal of sand fleas; on the other hand, sea urchins must 

 be picked up at low tide and in limited areas on exposed reefs or 

 other favorable spots. An island with extensive beaches, either 

 sand or gravel, is favorable for foxes. An island with a rocky 

 shore, and with few or no beaches, is not satisfactory; here, the 

 foxes must rely on sea birds, as long as the bird colonies last. 

 Throughout the Aleutians, life is concentrated pretty much along 



