What’s the difference between a seal and a sea lion? You can easily see a sea lion’s ears—just look for the little flaps of skin on the sides of the head. Seals don’t have ear flaps, just tiny ear openings.
Never timid about speaking what’s on their minds, sea lions make all sorts of barks, honks, trumpets, and roars. During the breeding season, bulls bark loudly and continuously to establish or defend their territories. A baby sea lion, called a pup, can pick out its mother from among hundreds gathered on rocky shores just by the sound she makes.
Sea lions are mammals and must breathe air, but they need to dive to catch food. With the help of nostrils that pinch closed automatically, a sea lion can stay underwater for up to 40 minutes at a time.