Seals and sea lions, along with walruses, belong to a group of marine mammals called “pinnipeds.” Pinniped means fin or flipper-footed in Latin. These animals spend the majority of their time in the ocean, but come on shore for long periods of time. Let us talk about Sea lions and Walrus.
Sea Lions
Sea lions are a group of marine mammals belonging to the family Otariidae. They are adapted to life in the ocean and are found along coastal regions around the world, usually in temperate and subarctic waters (Pacific waters).
Sea lions are characterized by their streamlined bodies and a coat of short coarse hair that lacks an undercoat. Except for the California sea lion (Zalophus californianus), males have lion-like manes and constantly roar to defend their harems (hence their name).
Sea lions are characterized by external ear flaps, long fore flippers, and a big chest and belly. They have short, thick fur, covering a thick layer of blubber that helps to keep them warm in the ocean. They have adapted features that help them to thrive on land and at sea. For example, the flippers at the end of their limbs help them to swim. Sea lions are able to rotate their hind flippers forward to help them scoot around on land.
Adult sea lions in length can be from 5 to 8 feet (1.5 to 2.4 meters) and can weigh between 200 to 1,000 pounds (90 to 450 kilograms), depending on the species. California sea lions, for example, are on the smallest while Steller sea lions are among the largest of all sea lion species.
They mostly feed on a diet of fish, squid, crabs, and clams. They are known for their agile and skilled hunting techniques, while they have teeth, sea lions often swallow their food whole. If needed, they’ll use their flat back teeth to crush food, like shells, before swallowing. Sea lions are known to be opportunistic feeders, and they often hunt in groups to herd schools of fish or corner their prey.
Sea lions are powerful and agile swimmers. They can swim at high speeds and are known for their acrobatic displays in the water. Their long, strong flippers and streamlined bodies enable them to navigate the ocean with ease. Sea lions are also capable of leaping out of the water, a behavior known as “porpoising,” which helps them breathe and cool off while swimming.
Sea lions are typically found in coastal areas, rocky shores, and islands, where they haul out onto land for resting, breeding, and giving birth. Various species of sea lions are distributed around the world, with California sea lions found along the western coast of North America and Steller sea lions inhabiting parts of the North Pacific Ocean, including Alaska.
Walrus
Walrus also referred morse are large marine mammals belonging to the family Odobenidae. They are uniquely adapted to life in the frigid Arctic waters. There are two subspecies: the Atlantic walrus (Odobenus rosmarus rosmarus) and the Pacific walrus (O. rosmarus divergens).
Walruses have a bulky, barrel-shaped bodies. They are easily recognizable by their prominent long tusks, which are actually elongated canine teeth. Both males and females possess tusks, although those of males tend to be larger and longer. These tusks can grow up to several feet in length. Walruses also have tough, wrinkled skin and a layer of blubber underneath to help them maintain body temperature in freezing conditions.
The walrus has a rounded head, small eyes, and no external ears. Its muzzle is short and broad and has a conspicuous moustache of stiff, quill-like whiskers (vibrissae). Among the pinnipeds (seals and sea lions), adult walruses are among the largest with lengths of about 7 to 12 feet (2.1 to 3.7 meters). They can weigh a substantial amount, with males reaching weights of 1,000 to 3,700 pounds (450 to 1,678 kilograms).
Walruses are bottom feeders and have a diet composed of benthic invertebrates found on the ocean floor. Their favorite prey includes clams, snails, worms, and other mollusks. To locate and extract these prey items, walruses use their sensitive vibrissae (whiskers) to detect food on the ocean floor. They use their tusks to create holes in the ice or sediment, and they use suction to draw out their prey.
While walruses may not be as agile in the water as some other marine mammals like sea lions, they are still capable swimmers. They can cover long distances in the ocean and usually migrate between their feeding and breeding grounds. Walruses rely on their powerful flippers for propulsion in the water using a combination of forward and backward strokes.
Walruses are gregarious animals. They form large aggregations or haulouts on ice floes or coastal areas. These haulouts can sometimes consist of thousands of individuals, and they are used for resting, socializing, and giving birth.
Sea Lions and Walruses: Key Differences
| Feature | Sea Lions | Walruses |
|---|---|---|
| Taxonomy | Family: Otariidae | Family: Odobenidae |
| Size | Generally smaller, with lengths of 5-8 feet | Larger, with lengths of 7-12 feet |
| Weight | Lighter, weighing 200-1,000 pounds | Heavier, weighing 1,000-3,700 pounds |
| Body shape | Streamlined body with visible ear flaps | Bulky body with less defined ear structures |
| Flippers | Longer and more pointed | Shorter and broader |
| Tusks | No tusks, but canines are small | Prominent long tusks (both males and females) |
| Diet | Mainly fish and squid | Benthic invertebrates like clams and snails |
| Swimming | Strong swimmers, can leap out of water | Adequate swimmers, less agile in the water |
| Vocalizations | Communicate with barks and growls | Make clicking and bell-like sounds |
| Social structure | Form colonies with complex social hierarchies | Tend to be less social and form smaller groups |
| Range | Found in temperate and subarctic regions | Arctic regions, mainly in the Arctic Ocean |
| Habitat | Coastal areas, rocky shores, and islands | Ice-covered waters, ice floes, and coastal areas |
| Conservation status | Varies by species, some are endangered | Vulnerable and sensitive to climate change |