Elephant Seal Younglings

These young northern elephant seals were weaned at about four weeks old, when their mothers returned to sea for good. What follows is a fast that lasts anywhere from a month to two and a half months on the beach, fueled almost entirely by blubber that makes up over a third of a weaner's body weight. During those same weeks they teach themselves to hold their breath, dropping their metabolic rate by as much as half while lying still. Resting in cold water costs them less energy than resting in air, which is part of why groups like this one linger at the edge of the surf.