The walrus, Odobenus rosmarus, is an immense Arctic marine mammal that spends the majority of its life navigating the frigid waters and sea ice of the Northern Hemisphere. These animals are defined by their considerable bulk, which can exceed 3,700 pounds in adult males. Despite their relatively clumsy appearance when hauling out onto ice floes, walruses possess the physical adaptations necessary to be highly effective swimmers. Their speed reflects their need to forage efficiently and survive in a challenging, predator-filled environment.
Walrus Speed Metrics
The speed of a walrus varies significantly depending on whether it is traveling long distances or sprinting away from a threat. When moving at a steady, sustained pace, a walrus typically swims at an average cruising speed of about 4.3 miles per hour (7 kilometers per hour). This consistent, slower speed is energy-efficient and used for routine travel for a creature of this size.
Maximum burst speed is a powerful sprint used in moments of necessity. A walrus can achieve a top speed of up to 22 miles per hour (35 kilometers per hour) in short bursts, which is approximately 19 knots. This capacity for rapid acceleration is vital when survival demands it.
Anatomy and Propulsion
The walrus achieves powerful aquatic movement through specialized anatomy and swimming technique. Unlike true seals, which use a side-to-side body motion, the walrus relies primarily on its large, triangular hind flippers for propulsion. These pelvic fins employ an alternating, powerful stroke to drive the massive body through the water column.
The fore flippers, or pectoral fins, are shorter and squarer in shape and serve a different function. While the hind flippers generate thrust, the fore flippers are generally held close to the body for streamlining or used for precise steering and maneuvering.
A thick layer of blubber beneath the skin, which can reach up to six inches in depth, contributes to hydrodynamic efficiency. This blubber functions as insulation against the near-freezing Arctic water and as a means of streamlining the body, reducing drag. The blubber also contributes to buoyancy, helping the walrus maintain its position in the water column and conserve energy during deep dives.
Ecological Role of Swimming
The ability to swim is directly tied to the walrus’s feeding habits and survival strategy within its Arctic habitat. Walruses are benthic foragers, hunting for food such as clams and bivalve mollusks on the seabed. They use their aquatic mobility to dive repeatedly to depths often exceeding 30 to 40 meters, using speed to reach the bottom quickly.
Powerful swimming is also integral to migratory patterns and navigation through ice-covered seas. They use sustained cruising speed for long-distance travel, sometimes covering thousands of kilometers between feeding grounds and seasonal haul-out sites. The ability to sprint is a necessary defense mechanism, primarily used to evade large predators like the orca (killer whale).