Seal or Sea Lion?

Is that a seal or a sea lion?

These animals are in two separate groups, the Phocidae, which are true seals that likely evolved from the otters, and the Otariidae, which are the sea lions and fur seals, that likely evolved from bears.

Harbor Seals. Photo by Ron LeValley

On our coast, we see:

• Pacific Harbor Seals

• Elephant Seals

• California Sea Lions

• Steller’s Sea Lions

• Northern Fur Seals (occasionally offshore)

Seals V. Sea Lions

Seals and sea lions share many characteristics but there are a few important features we can use to distinguish them. The most obvious difference is seals are earless, but rather have ear holes. Their hind limbs are shaped and used like a fish’s tail with webbing between the toes oriented vertically and swept from side to side. On land, seals are not able to bring their hind limbs forward so they move by dragging themselves with their short, clawed forelimbs and humping the rest of the body forward.

Sea lions and fur seals have an external ear flap (longer and more conspicuous in the fur seals). Their forelimbs are shaped like bird wings and they essentially “fly” underwater. Their hind limbs are also flipper-like and can be rotated forward when they are on land so these animals can walk on all fours. That is why sea lions can be found high up on the rocks, while seals are always close to the water.

Seals feed primarily by diving to the bottom and foraging on bottom-dwelling organisms like fish, skates, and rays. They are capable of staying underwater for a long time. Elephant seals can stay underwater for almost an hour and can dive to 5,692 feet – over a mile!

Sea lions feed in the water column, chasing schools of fish like anchovies, sardines, squid, and salmon. They are incredibly maneuverable, and can swim very fast.