Walruses are marine mammals of the Arctic, recognizable by their prominent ivory features. Both male and female walruses possess these distinctive, elongated teeth. Unlike some other tusked species, all walruses carry them. These specialized biological tools are essential for survival in the harsh, icy environments of the North Pacific and North Atlantic Oceans. Their continuous growth pattern reflects evolutionary adaptation to polar life.
Anatomy: What Walrus Tusks Truly Are
Walrus tusks are not horns or antlers; they are elongated upper canine teeth, unlike the incisors of an elephant. The average walrus has about 18 teeth, with these two canines modified to project beyond the mouth. This ivory structure is primarily composed of dentin, a hard material that gives the tusk its strength.
The tusks originally possess a thin layer of enamel near the tip, but this exterior wears away quickly due to constant use in the ice and sediment. Inside, the tusk is a living structure containing a pulp cavity with blood vessels and nerve tissue, making them sensitive. This sensitivity provides tactile information as the walrus interacts with its environment. Continuous growth is enabled by formative tissues at the root, meaning they lengthen throughout the animal’s life.
Development and Sexual Presence
Both male and female walruses develop tusks, which emerge shortly after birth, typically during a calf’s first summer or fall. Since they grow continuously throughout the animal’s lifespan, tusk size can serve as a rough indicator of an individual’s age and overall health.
While both sexes possess them, there is a difference in size and shape. Male tusks (bulls) tend to be longer, straighter, and stouter than those of females (cows). A large male Pacific walrus tusk can reach 100 centimeters (39 inches), while female tusks usually max out around 80 centimeters (31.5 inches). This difference plays a role in social dynamics and signals maturity and dominance.
Essential Roles in Walrus Survival
The walrus utilizes its tusks as tools for navigating its icy habitat. One recognized function is “hauling out,” which involves using the tusks as anchors or ice picks to pull their bodies out of the water and onto ice floes or rocky land. This behavior is so distinctive that the walrus’s genus name, Odobenus, roughly translates to “tooth-walker.”
The tusks are also used for maintaining access to air in frozen areas, as walruses use them to puncture or chip away at thin ice to create breathing holes. This allows them to forage for food in areas otherwise inaccessible during the winter months. The tusks are not used for digging up prey from the seabed; that task is handled by sensitive whiskers (vibrissae), which detect clams and other invertebrates.
Beyond their use as tools, tusks are central to the walrus’s social life and defense. Males use their tusks in competitive displays and combat during the breeding season, with the longer, thicker tusks signaling higher social status and dominance. Both sexes use them to ward off predators like polar bears. Tusk size and condition are linked to the walrus’s ability to survive, reproduce, and thrive in the challenging Arctic ecosystem.