Cambrian: Opinion

How elephant seals at Piedras Blancas handled the heat wave

Young male elephant seals play ‘I'm bigger than you’ on the beach at Piedras Blancas.
Young male elephant seals play ‘I'm bigger than you’ on the beach at Piedras Blancas. Special to The Cambrian

During last week’s heat wave the elephant seals at Piedras Blancas lined up tightly together at the water’s edge to take advantage of the wet sand that was cooler than the dry sand. More than usual were swimming to cool off, and the rest were flipping sand onto their backs as a sunscreen. They spend most of their time foraging in the cold waters off Canada and Alaska, so this heat was unwelcome. But they seem to have no choice.

They are wired to come down to the rookery this time of year to molt, shedding a layer of skin and hair each year. One of the most interesting things about them is their regular schedule. While they travel alone in the sea, they know when it’s their turn to return to the rookery to molt. Different age groups arrive in different months in a sort of musical chairs rotation.

This age group, which we call juveniles, has included hundreds of seals this year, females and males between the ages of about 2 and 6 years old. Many of them have shed their old tan and brown coats in bits and pieces to reveal a silvery gray new coat. They don’t eat during the three to four weeks that they are here, and as each one finishes its molt, it will return to the sea, most of them heading north to forage for creatures like squid, skates, octopus and other deep dwelling prey. They are known to dive as far as a mile deep and can go right along the continental shelf searching for food.

As these juveniles leave the beach, the next age group is beginning to arrive one by one. These are the subadult males, the seal version of teen-age boys. They can be identified by their larger size, but also by their growing noses — the proboscis that gives elephant seals their name. They also have different personalities from the younger seals.

Male aggression has started to set in, and they begin playing the male seals’ favorite game, “I’m bigger than you.” One will approach another male of about the same size and if the other one doesn’t chicken out and run away they will stretch their necks up to show off their size and begin sparring, banging necks together in pretend fights, but seldom actually biting as they will when they are adults fighting for mating rights.

When the subadults are leaving, the adult males will begin to arrive to molt in July, back from their migration to Alaska, where they travel twice a year. It’s understandable that they make that long journey back here in the winter for the mating season, but it seems like a long way to swim just to shed a layer of skin.