224 



NORTH AMERICAN FAUNA 74 



40 



30 



20 



10 



0^ 



fll 



10 



20 



30 



40 



30 



20 



J 



10 



20 



30 



Age ( years) 



Fig. 127. Examples of age composition of walruses in recent harvests by Alaskan 

 Eskimos: left, males taken at Gambell, Savoonga, and Diomede in spring 1962; right, 

 females taken at Gambell and Diomede in spring 1961. (From Alaska Department of 

 Fish and Game, unpublished data) 



Although their thick, tough skin provides some protection from such tusk strikes, 

 severe injuries occur in some instances. Also, because these animals tend to crowd 

 together on the haulouts, there is some traumatization, especially of the young, 

 by trampling (Tomilin and Kibal'chich 1975). 



Damages Caused by Tusk Strikes 



Walruses characteristically have an abundance of minor scars and lacerations 

 of the skin, especially on the neck and shoulders. Most of these are no more than 

 1 to 3 cm long and 2 to 5 mm deep, penetrating the epidermis but little more. 

 They are more noticeable on males than on females, possibly because of the 

 sparser pelage on the males; also they are more apparent on adults than on the 

 young, possibly for the same reason. Their distribution on the body seems to 

 correspond in general to that of strikes received from the tusks of opponents 

 (Miller 1975fl), indicating a simple cause-effect relationship. Walruses of both 

 sexes and all ages strike one another with their tusks, principally while engaging 

 in selection or defense of a resting place on land or ice. The adults, being more 

 powerful than the young, tend to cause more damage. 



Large, deep wounds occur commonly in adult males but are uncommon to 

 rare in adult females and younger animals. Such wounds occasionally are 

 punctures that penetrate the skin and blubber but more often are tears into the 

 dermal layer of the skin. These wounds tended to be open and bleeding in males 

 that I sighted in the St. Lawrence wintering area in March but were mostly 

 healing and draining in males that I saw there in April and May (Fig. 128). On 

 the males at Round Island in June and July, most of the wounds already were 

 well healed or at least farther advanced in healing than those seen earlier. For 

 these reasons, I believed that most of the major wounding of adult males takes 



