Stellar sea lions are easy to differentiate from harbor seals. First, they are larger. Second, stellar sea lions have articulated flippers that bend, enabling the sea lions to climb. Seals don't have this type of flippers. So, if you see a furry animal lounging on a buoy or a high rocky island like Marble Island, it is a stellar sea lion. The third way to tell a sea lion from a seal is that sea lions have exposed ear folds, and seals do not.