THE SEA OTTER IN THE EASTERN PACIFIC OCEAN 307 



Table 64. — Comparison of daily activities of wild and captive female sea 



otters in summer 







Wild otter 



Captive otter 





21 August 1955 1 



29 August 1957 



Activity 



Minutes 



Percent 



Minutes 



Percent 



Feeding ... 



257 



55 



81 



9 



Grooming 



50 



11 



445 



48 



Resting 



126 



28 



172 



19 



Exercise and play 



25 



6 



217 



24 



Total 



448 



100 



915 



100 



^ See Breeding Behavior for further data. 



time in this activity. The wild otter nearly satisfied her need for 

 exercise while diving for food. The captive satisfied this need by 

 swimming and grooming to a greater degree than the wild otter. 

 The percent of time devoted to rest by both animals differed the 

 least. 



BEHAVIOR AT NIGHT 



From 1 January to 9 September 1958, Mr. Cal Pierce, night 

 watchman at the Seattle Zoo, recorded observations of the behavior 

 of two captive sea otters. The objective was to obtain observations 

 of the time each animal spent in and out of the water and in the 

 den. For a variety of reasons, some nights were missed ; substitute 

 watchmen did not always properly record the data. Usable obser- 

 vations were taken on 199 of the 252 nights. Observations were 

 usually made at hourly intervals from 1800 to 2200, and two to 

 four times between 2200 and 0600. Usually the watchman recorded 

 only whether each animal was in the pool, beside the pool, or in 

 the den. Two dens were available, and both sea otters always had 

 free access to all areas within their enclosure. Weather conditions 

 were not recorded during the observation periods, but on several 

 occasions the watchman noted that even during heavy rain the 

 otters remained in the open, sleeping in or beside their pool. 



Feeding, grooming, and play were not recorded systematically, 

 but were noted on a number of occasions at various times during 

 the hours of darkness up to about 2200. During late night and early 

 morning hours, however, the animals usually slept quite soundly. 

 Sometimes they awoke with a start in the light of the watchman's 

 flashlight. If beside the pool when awakened, they immediately 

 plunged into the water ; if sleeping on the water, they would dive. 



Observations made after 9 September are not used. About this 

 time the behavior of the male became abnormal, and he spent in- 



