THE SEA OTTER IN THE EASTERN PACIFIC OCEAN 221 



interest, or even protective behavior, tov^^ard the male. What might 

 be interpreted as protective behavior v^as exhibited by an adult 

 female of an apparently mated pair that slept close beside each 

 other on tidal rocks at 1630 on 2 March 1962. The more alert female 

 started to leave the rock when she saw me approaching. When 

 the sleeping male failed to awaken and follow her, she returned 

 to him and, after pressing her paws against his face, neck, and 

 chest and crawling on top of him, she finally aroused him. She 

 then pressed her body against him from behind, inducing him to 

 enter the water and follow her out of the area (figs. 88 and 89). 



BREEDING BEHAVIOR VS. SOCIAL BEHAVIOR 



Barabash-Nikiforov (1947) stated that "A grown cub often 

 remains with the mother even after a new one is born, so that 

 the mother is seen together with the newborn and yearling." This 

 statement implies that a mother accompanied by a pup may 

 participate in breeding activity. Murie (1940) describes a situation 

 he observed in the Aleutians in which it appeared that the mother 

 of a young pup engaged in coitus while the "little one . . . was cry- 

 ing at the far edge of the kelp." 



I have observed a mother with a pup engage in rough play with 

 a courting male during which the male attempted coitus. I have 

 not, however, seen a female accompanied by a pup complete coitus 

 or participate with the male in the breeding behavior cycle. In all 

 instances that I have observed, the mother, after a period of play 

 with the male, eventually retrieved her pup and attempted to 

 disengaged herself from the aggressive male. If the pup was 

 large, the mother appeared to be considerably mauled as the crying, 

 clinging pup clasped her about the head and neck from the front 

 and the male clung to her from the rear, or tried to intrude be- 

 tween the mother and pup. My observations lead me to believe that 

 it would be difficult for a mother with a pup to engage in the mating 

 cycle of several days duration. 



That a mother accompanied by a pup might become impregnated 

 is a possibility. Further data on the physiology of reproduction in 

 the female must be obtained before a conclusion could be indicated 

 with some certainty. Available observations indicate to me that 

 it is usual for females to enter estrus only when they are not 

 accompanied by a pup. 



Certain habits of the sea otter could lead to confusion during 

 field observations. First, rough play might be mistaken for copu- 

 lation. It appears that Fisher (1939) may have made this mistake. 

 Second, sea otters, especially juveniles which are separated from 



