You’re paddling along through the harbor or glance out to sea from your campsite and see a roundish head poking up through the surface. Quick, what is it? Sea lion or harbor seal?
I’m Sunny Rice with the Petersburg Marine Mammal Center.
At first glance, and from a distance, it might be hard to determine if you’re looking at a seal or a sea lion, but there are some important characteristics, other than just size, that should help you figure it out. Their vocalizations are the first indication. Whereas seals are relatively quiet and unassuming, sea lions are quite noisy and are known for their loud barks.
Sea lions have pointier noses than seals, which have rounder heads. But their heads reveal another key difference. Stellar sea lions are called Otariids, or eared seals, because they have a small flap of skin over their ear holes. They are known for their speed and maneuverability, which means you’ll more likely see a sea lion move forward and bring its back up to dive before it disappears from view. You may also see them leaping completely out of the water. Have you ever seen them hauled out on a buoy? Yep, they’re agile enough to jump clear out of the water onto the cans.
Sea lions spend more of their time out of the water, hauling out to mate, rest and rear their young, so they’ve evolved to be a bit less awkward on land than seals. They are quadrupedal on land, which means they can pull their hind and fore flippers under them to ‘walk’ while maneuvering on shore. Although you could hardly call them graceful on land, their movement in the water is another story. They use their fore flippers to sail smoothly through the water, making quick turns to pursue their prey.
Harbor seals, on the other hand, have no ear flaps, and are part of the family called Phocids. They are much smaller than sea lions and are more likely to simply sink slowly downward until they are submerged out of sight when disturbed. They have small fore flippers, and their hind flippers extend straight back. Their flippers cannot be moved forward to help them walk on land. Instead, they wiggle their bodies like an inch worm over the ice or rock. In the water, those fixed hind flippers move side-to-side to propel them forward.
So now, the next time you see something peering at you from the surf, you might have a better chance at determining whether it’s an Otariid or Phocid!
