The walrus, a marine mammal of the Arctic and sub-Arctic seas, is instantly recognizable by its long, prominent tusks. These structures are elongated upper canine teeth that grow continuously throughout the animal’s life. Both male and female walruses possess tusks, though those of males tend to be longer and thicker, sometimes reaching up to one meter. The Latin genus name for the walrus, Odobenus, translates to “tooth-walker,” hinting at the multi-functional role these tools play. Tusks support locomotion, help secure food, establish social order, and provide a means of self-defense.
Movement and Stability
The tusks function primarily as physical aids for navigating and resting in the icy domain. When emerging from the water to rest, a process known as “hauling out,” the walrus uses its tusks as grappling hooks. The animal embeds the tusk tips into the ice floe or rocky shore and uses the leverage to pull itself out. This action is important given the walrus’s considerable weight, which can exceed 2,000 pounds for males, helping conserve energy.
The tusks also provide stability on slippery surfaces, acting as ice picks to prevent slipping. Walruses have been observed testing ice thickness with their tusks before hauling out, suggesting a sensory function that gauges platform stability. In areas where sea ice is thick, the walrus uses its tusks to create and maintain breathing holes by striking upward to fracture the ice. Accessing air expands their winter foraging range and aids survival when ice cover is extensive.
Foraging for Food
Walruses are specialized benthic feeders, foraging for soft-bodied invertebrates like clams, marine worms, and mollusks that live within the ocean floor sediment. The tusks are used to rake or plow through this sediment, disturbing the seabed to expose prey items. This action broadly displaces the substrate rather than involving precise excavation.
Once the sediment is disturbed, the walrus relies on its sensitive vibrissae, or whiskers, to locate the dislodged organisms. The walrus then uses powerful suction, created by pulling back its tongue, to extract the soft tissue from the shells. In areas of strong underwater currents, the tusks can be temporarily anchored into the substrate, allowing the animal to maintain its position while foraging. Analyzing tusk wear patterns often shows abrasion consistent with this sediment-plowing behavior.
Social Status and Defense
Beyond their utility as physical tools, walrus tusks indicate social standing and are employed in conflict resolution. Tusk size and condition measure an individual’s dominance, health, and fighting capability within the herd. Males with longer, more robust tusks generally have a higher social ranking and greater success during the breeding season.
During the mating period, males engage in ritualized sparring and fighting to establish a hierarchy, using their tusks as weapons. These encounters often result in visible scars on the neck and shoulders of older males, involving thrusting and jabbing at rivals. The tusks also serve as defensive weapons against the walrus’s few natural predators, such as polar bears and killer whales. When threatened, walruses form a protective circle around their young, positioning their tusks outward to deter an attack.