The Cambrian

It’s a tough life for elephant seal pups as they begin their migration from Piedras Blancas

Watch baby elephant seals at Piedras Blancas

The annual return of the elephant seals is underway at Piedras Blancas, California, starting off with pup season and then breeding at the beach on Highway 1 near San Simeon.
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The annual return of the elephant seals is underway at Piedras Blancas, California, starting off with pup season and then breeding at the beach on Highway 1 near San Simeon.

This year’s weaned elephant seal pups look grown up now, with their new, mature skin. They’re fat and ready to set off on their first migration.

A few thin males linger on the beach, resting a few more days before they depart for northern waters. They’ve been on the beach for as long as 100 days without food. They are at the physical low point of their year. They’ll spend the next four or five months feeding along the continental shelf of North America. They’ll be back in July and August with tons more blubber.

A few adult females showed up on the beach. They look fat and healthy, but not yet peeling off their skin in the annual molt. They may be seals that have skipped having a pup this year. Although over 90 percent of females have a pup every year, some don’t. Those that aren’t pregnant may arrive on the beach early, in October and November, or late, in early March.

Patrick Robinson, director of the Ano Nuevo Reserve, has seen these late-arriving female seals that haven’t given birth mating with males.

“We definitely have a few observations of females skipping the breeding season and coming back for as little as a single day in March to breed,” he said. “It’s hard to know for any individual untagged seal, but they can definitely get back on schedule quickly if they skip breeding for a year.”

Most of the seals on the beach are the Class of 2019 weaners. They are born black, but molt that newborn coat after they are weaned. Their new skin is dark on top, light on the belly.

It’s call countershading, and gives them some camouflage from predators. The light belly blends with the bright light of the surface to predators looking up from below. The dark back blends into the dark depths to predators looking down from above.

They spend most of their time sleeping, but one at a time, they venture into the surf. Some have already left, migrating north. No one shows them the way. It’s one of the mysteries of animal migration. Some may get as far north as Alaska, but most probably don’t get that far.

About half survive to return from that first migration in September. It’s a tough world out there. The half that don’t make it probably either can’t find enough food or are eaten by predators.

Starving weaners are already washing up on area beaches and being rescued by teams of volunteers from The Marine Mammal Center. Call TMMC in Morro Bay at 805-771-8300 if you see one on the beach. Center volunteers will monitor the pup for 24 hours or more, depending on the situation and, if necessary, rescue it safely.

Check the TMMC “current patients” page for updates on rescued weaners. Stay back 100 feet or so from a stranded seal. Rescued weaners are appealing, but they need to stay wild so that they can be rehabilitated and released to their home.

Christine Heinrichs is a certified California Naturalist who writes about wildlife.

For many years, elephant seal “bachelors” have rested periodically at the Hearst San Simeon State Park, taking a break from the winter breeding-and-birthing melee at the rookery 4.3 miles to the north.

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