214 



NORTH AMERICAN FAUNA 68 



in other island populations. Knowledge of the degree of segregation 

 of sexes and the locations of areas where males concentrate may 

 prove useful in management operations. 



As mentioned elsewhere (Breeding Behavior), males often 

 patrolled female feeding areas and attempted courtship with all 

 females present. In the course of 3 or 4 hours, two to four males 

 might pass separately through such an area. 



Breeding Behavior 



Observations at Amchitka are often hindered by dense fog. This 

 fact and the tendency of mated pairs of otters to occupy offshore 

 rocks, have prevented me from following any one pair of otters 

 through all phases of the breeding cycle. I have, however, recorded 

 observations of 41 mated pairs in the wild. Among these, copu- 

 lation was initiated by 13 males which were not successful in 

 completing it. Copulation was completed, apparently successfully, 

 in eight cases. The remaining 20 observations were of paired 

 animals in close company which, as explained later, exhibited the 

 behavior typical of mated pairs. Excluded from the records are 

 observations of unsuccessful attempts at courtship by males 

 toward unreceptive females. The data on various aspects of the 

 breeding cycle were obtained from many pairs observed briefly 

 and from the observation of one pair which remained for about 

 31/2 days in a sheltered cove (table 45). These observations in- 

 dicate that the cycle of breeding behavior is rather uniform. A 

 description of behavior during the different phases of the breeding 

 cycle follows : 



COURTSHIP OR PREGOPULATORY PERIOD 



As mentioned elsewhere, adult males and adult females segre- 

 gate themselves to a considerable degree. When a male seeks a 



Table 45. — Activities of a mated pair of sea otters during observations on 

 19, 20, and 21 August 1955 



19 August, 1634-1810. The male and female remained in close company at 

 all times. 









Elapsed time 











Number 



(minutes) 





Percent 







of 







Total 



of 



Activity 





periods 



On land 



In water 



minutes 



time 



Copulation 









35 



35 



37 



Grooming 







39 



2 



41 



43 



Sleeping . 





1 



19 





19 



20 



Total- 





5 



58 



37 



95 



100 



