Homing Behaviour in an Atlantic Walrus (Odobenus rosmarus rosmarus)

An adult Atlantic walrus (Odobenus rosmarus rosmarus) male (31 years old in 2001) tracked by use of satellite telemetry in NE Greenland during four seasons (1989, 1990/1991, 2000/2001, 2001) revealed a remarkably high perennial tendency of homing and consistency of migration pattern. During all four inshore summering periods (August to September), the animal used only one terrestrial haul-out from which it made excursions to the same general shallow water area (i.e., likely clam beds) in western Dove Bay (ca. 76º to 77º N). In different years, the size of the inshore foraging area varied between 48 and 86 km2 in August, and between 136 and 385 km2 in September. The inshore foraging period lasted ca. 69 days in 1989 and 1990, but ca. 86 days in 2000 (no data for 2001). During fall 1989, 1990/1991 and 2000/2001, the walrus followed the same migration route in the Greenland Sea north to the wintering grounds in the Northeast Water polynya (ca. 79º to 81º N). Apparently, this movement pattern was relatively independent of annual variations in ice and temperature regimes. Offshore in the Greenland Sea–Fram Strait area, the walrus occurred mainly in areas with dense ice cover (> 90%). During both the inshore summer and offshore winter, the animal dived to at least 250 m (maximum depth limit of the transmitter). The tracking of this walrus, whose activity pattern was typical of male walruses in the region, shows that this stenophagous species is a creature of habit with a highly stereotypic movement pattern which apparently is influenced by the location of predictable feeding, wintering, and mating areas.