"A weaned harbor seal pup was resting onshore when an untagged male sea otter approached it, grasped it with its teeth and forepaws, bit it on the nose, and flipped it over. The harbor seal moved toward the water with the sea otter following closely. Once in the water, the sea otter gripped the harbor seal’s head with its forepaws and repeatedly bit it on the nose, causing a deep laceration. The sea otter and pup rolled violently in the water for approximately 15 min, while the pup struggled to free itself from the sea otter’s grasp. Finally, the sea otter positioned itself dorsal to the pup’s smaller body while grasping it by the head and holding it underwater in a position typical of mating sea otters. As the sea otter thrust his pelvis, his penis was extruded and intromission was observed. At 105 min into the encounter, the sea otter released the pup, now dead,and began grooming...
Bizarre as this behavior may seem, Harris and her co-authors point out that it is not dissimilar to standard sea otter mating protocol, in which males will often approach the female from behind, grip her around the chest with his forepaws, and grasp her nose or the side of her face with his teeth. Although the female frequently resists, generally the two eventually spin in the water, the male behind the female, until mating is complete. Here, too, the encounters may prove fatal for the female, either as a result of wounds inflicted from the male’s bites and scratches or because of drowning. Harris and colleagues describe one instance in which a male otter held a struggling female underwater until her body became limp and then copulated with her several times. Indeed, trauma related to mating was responsible for 11 percent of deaths in fresh southern sea otter carcasses examined between 2000 and 2003. "-Heather Harris, California Department of Fish and Game
