Tuesday, April 27, 2021

The seals molt their skin

 The Piedras Blancas elephant seal rookery is full of seals now, but that signature trunk-like nose isn’t among them. It’s adult females and young seals on the beach in the spring, molting their skin.



Adult bulls, the ones with the floppy noses, are out at sea bulking up after three months without food during the breeding season. They’ll return, fat and blubbery, in the summer for their annual molt.

Seals are arriving by the hundreds, to rest on the beach during the busiest time of the year. More seals are on the beach in May than even during breeding season. Look for unusual scars, colored identification tags and dyed identification markings.

Short migration

Female elephant seals make two annual migrations, the short one after the breeding season and the longer one after molting. After giving birth and nursing their pups during the winter breeding season without food, they are thin and need to eat. They leave their weaned pups on the beach and swim away for ten weeks or so, feeding and putting on the blubber. They need it to survive in their cold ocean home and to sustain them while they are on the beach for six weeks, when they do not eat at all.



The beach fills up with females and juveniles of both sexes. That’s 5,600 females who had pups on the seven or so miles of beaches that are considered the Piedras Blancas rookery, the females who didn’t have a pup this year, and countless juveniles. 

Molting

They arrive on the beach one by one, on their individual time schedules. The new, pearly gray skin is already forming beneath the old skin. Within a few days, the old skin begins to peel off – first around body openings such as eyes and around permanent scars. The old brown skin curls back and falls off.

They look ratty, but they’re fine. It’s normal, a ‘catastrophic molt.’ Elephant seals spend much of their lives 1,000 feet and deeper in the ocean. The pressure and the cold at that depth may account for the unusual annual molt. 



Molting takes about six weeks. Since seals arrive on the beach individually, starting and stopping at different times, seals are at all stages of molting in April and May. Some already have their new pearl gray skin, while others are just arriving. Look for the ragged edges of skin peeling back, seals that are entirely brown or entirely gray.

Weaned pups

Nearly all the season’s weaned pups have left on their first migration. About half make it, to return in the fall. Struggling pups make strand on local beaches. If you encounter one, you can report it to the Marine Mammal Center operations center in Morro Bay at (805) 771-8300. They will send out a team to evaluate it and rescue it if necessary.

Visitors can learn about the seals from the brochures available at the boardwalk and on the FES website, https://www.elephantseal.org/,. Friends of the Elephant Seal docents have not yet been cleared to return to helping visitors understand what they are seeing due to Covid restrictions.