CALIFORNIA SEA LIONS

The clichéd circus seal—obligingly balancing a ball on its nose and jumping through hoops—is typically a California sea lion.

But in the wild, the California sea lion is a sleek animal, faster than any other sea lion or seal. These eared seals top out at speeds of some 25 miles (40 kilometers) an hour. Unlike other sea lions, California sea lions do not have lionlike manes.

These pinnipeds live along the rocky Pacific Ocean coastlines of western North America and also near Ecuador's Galápagos Islands. Huge colonies can be seen gathered on seaside rocks, and even on man-made structures, for breeding and for birthing. Males gather harems of females to their sides in competition to sire young pups, which are born on land.

The sea lion's ancient ancestors, like those of whales and dolphins, lived on land. The modern animal is well adapted to an aquatic environment, with its streamlined body and powerful flippers. (The rear flippers rotate forward to allow a California sea lion to move surprisingly well on land.) California sea lions also boast thick layers of blubber to insulate their bodies from the chill of marine waters.

When diving deep, California sea lions slow their heart rates to allow them to remain underwater for nearly ten minutes before surfacing to breathe. This ability gives them an edge in the pursuit of the fish, squid, and shellfish that make up their primary diet.