308 



NORTH AMERICAN FAUNA 68 



creasing amounts of time in the den. His health steadily deteri- 

 orated and he died on 22 September. 



The general behavior pattern for each animal during the night 

 is indicated in figures 117 and 118. Both animals tended to remain 

 in the water more than out of it during the early evening hours. 

 During late night and early morning hours, the male spent a nearly 

 equal time in and out of the water while the female tended to spend 

 more time out of the water than in it. Both animals preferred to 

 remain out of doors, whether sleeping on the pool edge or in the 

 water, but the female consistently spent more time in the den 

 than did the male. 



Even during winter months the sea otters seldom sought shelter 

 in the den (figs. 119 and 120). The amount of time spent in the 

 water at night, however, was greatly reduced in winter months. 

 The male spent only 20 percent of the night in the pool during 

 January. During the spring and summer the amount of time he 



Figure 117. — Behavior of an adult male sea otter during a mean or average 

 night. The mean percent of 1,185 observations of the animal in three loca- 

 tions during the night are shown. 



