Summary
Walruses (Odobenus rosmarus) feed primarily on benthic invertebrates, but they are known to eat seals (Phocidae) occasionally, ostensibly when the benthic foods are unavailable. We investigated reports of a marked increase in occurrence of seal-eating walruses in the Bering Strait region in the late 1970's by examining stomach contents of animals taken in the spring harvests by Eskimos. We also obtained relevant information during visual surveys of marine mammals in the region. Our findings from the stomachs indicated that seal eating was 10 to 100 times more common during the 1970's and early 1980's (0.6–3.0%, N=645) than it had been in the previous three decades (0.07–0.20%, N=4015). In addition, we observed walruses in possession of seal remains in 1978 and 1979, where we had not seen such a phenomenon before in the previous 25 years. We attribute the increased predatory interaction between seals and walruses partly to a larger walrus population and, especially in 1979, to unusually restrictive spring ice conditions, which tended to cause greater than usual overlap of their distributions. Stomach contents of walruses taken in the Chukchi Sea in summer, where the ranges of walruses and seals overlap broadly in all years, have indicated a similarly high rate of occurrence of seal eaters (8.6% in the 1960's, N=35; 11.4% in 1983, N=44). As a whole, our findings indicate that most of the seal eating is predation, rather than scavenging of carrion. They also indicate that it is not rare or aberrant but common behavior, and that it could exert a significant impact on seal populations in some areas.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Braham HW, Burns JJ, Fedoseev GA, Krogman BD (1984) Habitat partitioning by ice-associated pinnipeds: distribution and density of seals and walruses in the Bering Sea, April 1976. In: Fay FH, Fedoseev GA (eds) Soviet-American cooperative research on marine mammals, vol 1, Pinnipeds. Natl Mar Fish Serv Circ Tech Rep (in press)
Brooks JW (1954) A contribution to the life history and ecology of the Pacific walrus. Spec Rep 1, Alaska Cooperative Wildlife Research Unit, University of Alaska, Fairbanks, 103 pp
Burns JJ (1965) The walrus in Alaska: its ecology and management. Alaska Dep Fish and Game, Juneau, 48 pp
Burns JJ, Shapiro LH, Fay FH (1980) The relationships of marine mammal distributions, densities and activities to sea ice conditions. In: Environmental assessment of the Alaskan continental shelf, final reports of principal investigators, vol 11, biological studies. NOAA Office of Marine Pollution Assessment, Juneau, Alaska, pp 489–670
Chapskii KK (1936) The walrus of the Kara Sea. Trudy Vsesoiuz Arkt Inst, Leningrad 67:1–124
Fay FH (1960) Carnivorous walrus and some arctic zoonoses. Arctic 13:111–122
Fay FH (1981) Modern populations, migrations, demography, trophics and historical status of the Pacific walrus. In: Environmental assessment of the Alaskan continental shelf, annual reports of principal investigators 1981, vol 1. NOAA Office of Marine Pollution Assessment, Juneau, Alaska, pp 191–234
Fay FH (1982) Ecology and biology of the Pacific walrus, Odobenus rosmarus divergens Illiger. U S Fish Wildl Serv N Am Fauna no 74, 279 pp
Fay FH, Feder HM, Stoker SW (1977) An estimation of the impact of the Pacific walrus population on its food resources in the Bering Sea. Final Rep U S Marine Mammal Commission, PB-273-505, National Technical Information Service, Springfield Va, 38 pp
Fay FH, Kelly BP (1980) Mass natural mortality of walruses (Odobenus rosmarus) at St. Lawrence Island, Bering Sea, autumn 1978. Arctic 33:226–245
Fay FH, Stoker SW (1982a) Analysis of reproductive organs and stomach contents from walruses taken in the Alaskan native harvest, spring 1980. Final Rep U S Fish Wildl Serv, Anchorage, Alaska, 86 pp
Fay FH, Stoker SW (1982b) Reproductive success and feeding habits of walruses taken in the 1982 spring harvest, with comparisons from previous years. Final Rep Eskimo Walrus Commission, Nome, Alaska, 91 pp
Freuchen P (1935) Mammals, 2. Field notes and personal observations. Rep Fifth Thule Exped 1921–24 2(4–5):68–278
Gray RW (1927) The walrus. Nature (London) 119:923
Krylov VI (1971) Food of the Pacific walrus (Odobenus rosmarus divergens Ill.). In: Milchenko ES, Andreeva TM, Burov GP (eds) Studies of marine mammals. Trudy Atlantic Sci Inst Fish and Oceanogr no 39. (Translated from Russian by Fish Mar Serv, Canada, Transl Ser no 3185)
Lowry LF, Frost KJ, Burns JJ (1981) Trophic relationship among ice-inhabiting phocid seals and functionally related marine mammals in the Bering Sea. In: Environmental assessment of the Alaskan continental shelf, final reports of principal investigators, vol 11, biological studies. NOAA Office of Marine Pollution Assessment, Juneau, Alaska, pp 99–173
Rausch RL (1970) Trichinosis in the Arctic. In: Gould SE (ed) Trichinosis in man and animals. Chas C Thomas, Springfield Ill, pp 348–373
Scheffler VB (1955) Standard measurements of seals. J Mammal 48:459–462
Smith TG (1980) Polar bear predation of ringed and bearded seals in the land-fast sea ice habitat. Can J Zool 58:2201–2209
Stirling I, McEwan EH (1975) The caloric value of whole ringed seals (Phoca hispida) in relation to polar bear (Ursus maritimus) ecology and hunting behavior. Can J Zool 53:1021–1027
Vibe C (1950) The marine mammals and the marine fauna in the Thule district (northwest Greenland) with observations on ice conditions in 1939–41. Medd Groenl 150:1–115
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Lowry, L.F., Fay, F.H. Seal eating by walruses in the Bering and Chukchi Seas. Polar Biol 3, 11–18 (1984). https://doi.org/10.1007/BF00265562
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00265562