Walruses do not possess legs in the manner of land mammals, but instead have specialized limbs called flippers. These adaptations allow them to navigate effectively in both their aquatic and terrestrial environments. Understanding these specialized features helps clarify how these large marine mammals interact with their Arctic habitat.
Specialized Walrus Anatomy
Walruses possess specialized limbs, called flippers, distinct from land animal legs. Both fore-flippers and hind-flippers are broad and paddle-like, designed for movement in water and on solid surfaces. The fore-flippers contain all the major skeletal elements found in the forelimbs of land mammals, but they are shortened and modified to suit an aquatic lifestyle. Each fore-flipper is short, square-shaped, and has five digits of roughly equal length, each with a small, inconspicuous claw.
The hind-flippers are triangular and also possess five bony digits, with the claws on the three middle digits being larger than those on the outer two. The skin on the soles of a walrus’s flippers is thick and rough, providing traction on slippery ice and land. Walruses also possess strong musculature that supports the movement of these flippers, enabling powerful propulsion in water and controlled locomotion on land. Unlike many seals, walruses can rotate their hind-flippers forward, a feature that significantly aids their terrestrial movement.
Movement on Land and in Water
Walruses use their specialized flippers for distinct methods of movement on land and in water. On land, they move in a unique shuffling or waddling gait, often described as “walking on all fours.” This involves rotating their triangular hind-flippers forward beneath their body to support their weight, similar to how sea lions move. They then use their fore-flippers, positioned at right angles to their body, to pull themselves along, heaving their massive bodies forward. Despite their substantial size, walruses can move surprisingly fast on land, sometimes matching the running speed of a human.
In water, walruses are agile and powerful swimmers, spending approximately two-thirds of their lives submerged. They primarily propel themselves using alternating strokes of their hind-flippers, which act like a propeller. Their fore-flippers serve a different purpose, aiding in steering, maneuvering, and maintaining balance. While swimming, walruses often hold their fore-flippers close to their body, deploying them for precise directional control. This powerful technique allows them to reach average speeds of about 7 kilometers per hour (4 miles per hour) and burst speeds of up to 35 kilometers per hour (22 miles per hour).