The easy way to tell the difference between seals and sea lions

March 21, 2017, 3:33 p.m.
Sea lions on the beach at twilight
Photo: Brendan van Son/Shutterstock

Have you ever found yourself wondering whether the seal in front of you is actually a sea lion? Have you been curious about what the differences really are?

Seals and sea lions are both pinnipeds, the group of fin-footed marine mammals often spotted lounging around beaches, rocky shorelines and piers. Pinnipeds include many species of seal, sea lion and the famously mustached walrus.

Two physical features set sea lions apart from other seal species, and they're easy to spot once you know what to look for.

First, sea lions have external ear flaps while seals don't. The sleek heads of seals are easily distinguished from sea lions when you look for these little flaps, which you'll notice on the young sea lion in the photo above. If you're looking at a fur seal, you might be thrown off slightly because this seal species also has external ear flaps. But most of the time, you're going to know pretty quickly whether you're looking at a seal or sea lion with this little physical clue.

The other clue is also shown in the photo above. Seals have weaker flippers and aren't able to use them to prop themselves up. You'll see them lying around like rotund sausages on rocks and beaches, and they wiggle on their bellies to move around on land. Sea lions, on the other hand, have more robust flippers, which they can use to maneuver around or prop themselves up on for a look around. Sea lions can also rotate their hind flippers — something seals cannot do — so they can "walk" on all four of their appendages.

So if you see a "seal" that's using its flippers to sit up or walk around, you know you're actually looking at a sea lion. And if you want to be extra sure, take a look to see if you spot ear flaps!