Northern Elephant Seal

Each December northern elephant seals heave ashore beaches from Baja to central California after completing another lap of the most demanding mammalian migration on earth. The only animals known to migrate twice annually, the seals have been known to log 13,000 Pacific miles a year. They also dive deep—up to 4,921 feet deep—in search of food.

Elephant seals earned their moniker due to the males’ trunk-like noses, which swell to issue rapid-fire drumbeats of defiance as they vie for territory during winter mating season. Only a lucky few win prime real estate and the ensuing female harems; most are doomed to bachelordom. Males are enormous—up to 16 feet long and 5,000 pounds—so the duels are thunderous affairs. Females are much smaller, 8 to 12 feet long and 1,000 to 2,000 pounds. Año Nuevo State Park boasts the largest mainland colony of northern elephant seals; guided tours are available from December to April. Piedras Blancas, just south of Big Sur near San Simeon, is another big rookery.

Freaky Fact: Elephant seals replenish their skin and hair cells the extreme way: they molt! The seals return to their mating rookeries every summer to shed skin and fur and replace it with a shiny new coat.

The seals spend most of their migrating time submerged, foraging at around 1,800 feet beneath the ocean’s surface for food and taking only moments to rest between dives. They have been known to stay down for two hours. Due to these serious free diving skills, scientists use Southern elephant seals—the northerners’ Antarctic counterparts—to map the ocean floor, discovering previously unimagined depths. The food must be good down there, because southern elephant seals are the largest in the world, weighing in at 8,800 pounds and reaching 20 feet in length.

—L. Clark Tate