sexes are thicker and heavier in the male than in the female, no external 

 ears are evident, and the hair-covered flippers are capable of being 

 rotated forward like those of a sea-lion,, The largest individual tusks 

 measured 39-1/2 inches in length (length along curve). A weight of nearly 

 12 pounds is recordedo The baculum or penis bone attains a length of 

 25 inches and a weight of over 2 poimds. The walrus is heavily whiskered 

 with stiff bristlep which may attain a length of 10 inches in captivity but 

 normally wear off short in the wild. 



Range 



The winter range of the walrus includes most of the Bering Sea north 

 of the Pribilof Islands. In migrating it rides for the most part on ice floes 

 which drift south to Bristol Bay in winter, north to Point Barrow in sum- 

 mer. The sexes tend to travel apart except at the breeding season. Occa- 

 sionally the walrus hauls out on land; recently over a thousand bulls were 

 counted on Walrus Island in Bristol Bay. Persistent hunting with firearms 

 has destroyed most of the populations which formerly hauled out on Bering 

 Sea beaches, with the result that the main herd now resorts to the ice 

 fields. From the evidence of skeletal remains and early accounts, the 

 southern limit of the range used to include the Shumagin Islands, in the 

 North Pacific, and the Pribilof Islands. Virtually nothing is known about 

 the intermingling of Siberian and American stocks. Biologists have esti- 

 mated at 15, 000 the greatest number of walruses present at any season in 

 Alaskan waters. While some walruses remain north of Bering Strait in 

 winter, most of them do not pass north through the Strait until June, or 

 after the calving season. 



Breeding habits 



Mating and calving take place on the ice in April and May. The ges- 

 tation period is 1 year. Among pinnipeds, the walrus is peculiar in that 

 the female does not mate in the same year that she calves, but rests for 

 a year or two in between. Twins are unknown. The calf remains with its 

 mother for about 2 years, gradually becoming independent. Like the sea- 

 lion, the female walrus has 4 nipples. The male walrus is thought to be 

 promiscuous; he does not attract a definite harem as does the bull fur seal. 



Feeding habits 



The walrus feeds mainly on clams obtained from the floor of the 

 Bering Sea and Chukchi Sea at depths down to 200 feet or more. Feeding 

 of the walrus has never been observed. It is believed that by means of its 

 tusks and stiff moustaches, the walrus stirs up clams, snails, echinoderms, 

 and worms. The contents of one bull walrus stomach included 85 poxmds of 

 clam "necks" and feet. The walrus manages to avoid swallowing the shells 

 of mollusks. Under certain xiircumstances a solitary or "rogue" walrus 

 may attack and eat chunks of the flesh of other pinnipeds such as the 

 bearded and ringed seals. 



18 



