Bruce Bagemihl - Biological Exuberance

Separation of the sexes continues through pup-rearing: like most polygamous animals, male Seals do not participate in any parenting duties. Females, however, engage in an assortment of fostering activities, often after they have lost their own pup (although some take care of other pups in addition to their own). More than half of all Northern Elephant Seal pups become separated from their mothers each season, and about 18 percent of all females adopt pups. Besides the female coparenting arrangements mentioned above, many females adopt orphan pups on their own, some female Elephant Seals nurse several orphans at once, while others nurse already weaned pups (who become bloated from the extra milk, turning into gigantic “superweaners,” as they are called). Some females even try to “kidnap” or steal pups away from their own mothers, and females who have not lost their own pup often threaten, attack, and even kill stray pups. As many as a quarter to three-quarters of female Gray Seals and 10 percent of female Harbor Seals participate in foster-parenting in some populations.

Pairs of female Spotted or Larga Seals (Phoca largha) occasionally coparent their pups together, even sharing in nursing their offspring. Male Sea Otters (Enhydra lutris ) have been observed clasping and mounting other males (in the water) in the position usually seen during heterosexual matings. Male Sea Otters also sometimes mount and attempt to mate with Seals, including Harbor Seals and Northern Elephant Seals, and some of these interactions may be same-sex.

*asterisked references discuss homosexuality/transgender

Allen, S. G. (1985) “Mating Behavior in the Harbor Seal.” Marine Mammal Science 1:84–87.

Amos, B., S. Twiss, P. Pomeroy, and S. Anderson (1995) “Evidence for Mate Fidelity in the Gray Seal.” Science 268:1897–99.

Anderson, S. S. (1991) “Gray Seal, Halichoerus grypus.” In G. B. Corbet and S. Harris, eds., The Handbook of British Mammals, pp. 471–80. Oxford: Blackwell Scientific Publications.

Anderson, S. S., and M. A. Fedak (1985) “Gray Seal Males: Energetic and Behavioral Links Between Size and Sexual Success.” Animal Behavior 33:829–38.

*Backhouse, K. M. (1960) “The Gray Seal ( Halichoerus grypus ) Outside the Breeding Season: A Preliminary Report.” Mammalia 24:307–12.

———(1954) “The Gray Seal.” University of Durham Medical Gazette 48:9–16.

*Backhouse, K. M., and H. R. Hewer (1957) “Behavior of the Gray Seal ( Halichoerus grypus Fab.) in the Spring.” Proceedings of the Zoological Society of London 129:450.

Baker, J. R. (1984) “Mortality and Morbidity in Gray Seal Pups ( Halichoerus grypus ) .” Journal of Zoology, London 203:23–48.

Bishop, R. H. (1967) “Reproduction, Age Determination, and Behavior of the Harbor Seal, Phoca vitulina L. in the Gulf of Alaska.” Master’s thesis, University of Alaska.

Boness, D. J., D. Bowen, S. J. Iverson, and O. T. Oftedal (1992) “Influence of Storms and Maternal Size on Mother-Pup Separations and Fostering in the Harbor Seal, Phoca vitulina.” Canadian Journal of Zoology 70:1640–44.

Boness, D. J., and H. James (1979) “Reproductive Behavior of the Gray Seal (Halichoerus grypus ) on Sable Island, Nova Scotia.” Journal of Zoology, London 188:477–500.

Burton, R. W., S. S. Anderson, and C. F. Summers (1975) “Perinatal Activities in the Gray Seal (Halichoerus grypus ). ” Journal of Zoology, London 177:197–201.

Coulson, J. C., and G. Hickling (1964) “The Breeding Biology of the Gray Seal, Halichoerus grypus (Fab.), on the Farne Islands, Northumberland.” Journal of Animal Ecology 33:485-512.

*Deutsch, C. J. (1990) “Behavioral and Energetic Aspects of Reproductive Effort of Male Northern Elephant Seals (Mirounga angustirostris ) .” Ph.D. thesis, University of California–Santa Cruz.

*Hatfield, B. B., R. J. Jameson, T. G. Murphey, and D. D. Woodard (1994) “Atypical Interactions Between Male Southern Sea Otters and Pinnipeds.” Marine Mammal Science 10:111–14.

Hewer, H. R. (1960) “Behavior of the Gray Seal ( Halichoerus grypus Fab.) in the Breeding Season.” Mammalia 24:400–21.

Hewer, H. R., and K. M. Backhouse (1960) “A Preliminary Account of a Colony of Gray Seals, Halichoerus grypus (Fab.) in the Southern Inner Hebrides.” Proceedings of the Zoological Society of London 134:157–95.

Hoover, A. A. (1983) “Behavior and Ecology of Harbor Seals ( Phoca vitulina richardsi) Inhabiting Glacial Ice in Aialik Bay, Alaska.” Master’s thesis, University of Alaska.

*Johnson, B.W. (1976) “Studies on the Northernmost Colonies of Pacific Harbor Seals, Phoca vitulina richardsi, in the Eastern Bering Sea.” Unpublished report, University of Alaska Institute of Marine Science and Alaska Department of Fish and Game; 67 pp. (available at National Marine Mammal Laboratory Library, Seattle, Wash.).

*———(1974) “Otter Island Harbor Seals: A Preliminary Report.” Unpublished report, University of Alaska Institute of Marine Science and Alaska Department of Fish and Game; 20 pp. (available at National Marine Mammal Laboratory Library, Seattle, Wash.).

*Johnson, B. W., and P. Johnson (1977) “Mating Behavior in Harbor Seals?” Proceedings (Abstracts) of the Conference on the Biology of Marine Mammals (San Diego) 2:30.

Kroll, A. M. (1993) “Haul Out Patterns and Behavior of Harbor Seals, Phoca vitulina, During the Breeding Season at Protection Island, Washington.” Master’s thesis, University of Washington.

*Le Boeuf, B. J. (1974) “Male-Male Competition and Reproductive Success in Elephant Seals.” American Zoologist 14:163–76.

———(1972) “Sexual Behavior in the Northern Elephant Seal, Mirounga angustirostris.” Behavior 41: 1–26.

Le Boeuf, B. J., and R. M. Laws (eds.) (1994) Elephant Seals: Population Ecology, Behavior, and Physiology. Berkeley: University of California Press.

Le Boeuf, B. J., and S. Mesnick (1991) “Sexual Behavior of Male Northern Elephant Seals: I. Lethal Injuries to Adult Females.” Behavior 116:143–62.

Le Boeuf, B. J., and J. Reiter (1988) “Lifetime Reproductive Success in Northern Elephant Seals.” In T. H. Clutton-Brock, ed., Reproductive Success: Studies of Individual Variation in Contrasting Breeding Systems, pp. 344–62. Chicago: University of Chicago Press.

Mortenson, J., and M. Follis (1997) “Northern Elephant Seal ( Mirounga angustirostris ) Aggression on Harbor Seal ( Phoca vitulina) Pups.” Marine Mammal Science 13:526-30.

Perry, E. A., and W. Amos (1998) “Genetic and Behavioral Evidence That Harbor Seal (Phoca vitulina) Females May Mate with Multipile Males.” Marine Mammal Science 14:178–82.

Riedman, M. L. (1990) The Pinnipeds: Seals, Sea Lions, and Walruses. Berkeley: University of California Press.

*Riedman, M. L., and B. J. Le Boeuf (1982) “Mother-Pup Separation and Adoption in Northern Elephant Seals.” Behavioral Ecology and Sociobiology 11:203–15.

*Rose, N. A., C. J. Deutsch, and B. J. Le Boeuf (1991) “Sexual Behavior of Male Northern Elephant Seals: III. The Mounting of Weaned Pups.” Behavior 119:171–92.

Smith, E. A. (1968) “Adoptive Suckling in the Gray Seal.” Nature 217:762–63.

Stewart, B. S., and R. L. DeLong (1995) “Double Migrations of the Northern Elephant Seal, Mirounga angustirostris.” Journal of Mammalogy 76:196—205.