THE SEA OTTER IN THE EASTERN PACIFIC OCEAN 217 



this period, the male may grasp the female about the chest from 

 behind with his forepaws and attempt to grasp the side or back of 

 her head or her nose in his jaws. At this rather rough stage of 

 courtship, the female may disengage herself, snap at the male, 

 and push him away with her flippers and paws. The two may now 

 separate, but if the female is not determined in her resistance 

 the male may follow her; or, occasionally, the female may follow 

 the departing male and rough courtship behavior will continue. 

 If the female is in estrus, she becomes increasingly submissive as 

 courtship continues. 



After the male has found an estrous female, the two continue 

 actively to roll and splash about on the surface together. They 

 nuzzle each other and fondle each other with the forepaws. Similar 

 behavior was noted in the polecat by McCann (1955). Such be- 

 havior apparently lasts for a variable period, perhaps up to an 

 hour. In the course of their activities the animals usually make 

 their way, with the female leading, toward a suitable hauling-out 

 rock which the female selects. This spot becomes the center of 

 their activities during the mating period. 



GOPULATORY PERIOD 



Copulation takes place in the water near the hauling-out rock. 

 When the female is ready for coitus, her body becomes rigid and 

 she lies belly up on the surface, her back somewhat bowed (i.e., 

 concave) and her forelegs rigid and protruding vertically in front 

 of her. The male grasps the female's upper jaw usually, including 

 her nose, in his jaws, or he may grasp the side of her head. If the 

 mated pair are on land during precoital play, the male leads the 

 female into the water after grasping the side of her head in his 

 jaws. He clasps her tightly from the back ("more canum"), his 

 paws resting against her chest in or near her axillae. At the same 

 time the already extruded penis is inserted as the male rests 

 against the female's back, slightly on one side of the mid-dorsal 

 area. The rear feet of the male are in motion, so that the two 

 animals move about in a wide circle and roll from side to side. 

 Periodically they lift their noses above the surface. For the most 

 part, the male is beneath the surface and the belly and chest of 

 the female are above it. The female frequently emits loud shrieks 

 and gurgling gasps which indicate that she experiences difficulty 

 in breathing. 



In one case (19 August 1955), after copulation had continued 

 for 14 minutes, the female struggled and wrenched her body, 

 disengaging the male's penis. The male, however, retained his grip 



