Once elephant seal pups are weaned, they must learn to swim

Now that the elephant seal pups are weaned, they enter the next stage of life: learning to hold their breath and swim, to prepare for their first migration. Watch them enter the water and splash around. The shallow water and rocky coastline protect them from their predators, great white sharks and orcas.

They spend a lot of time sleeping on the beach. That doesn’t mean nothing is going on. Their metabolism is changing, from rapidly gaining weight as they nurse to living off their blubber. They won’t get anything more to eat until they enter the ocean and begin hunting for their own food. It will take a month or more before they eat again.

Long fasts are common among marine mammals. As adults, elephant seals fast during their four- to six-week molt every year. Females fast during the month they are on the beach to give birth and nurse their pups. Males fast as long as 100 days during the breeding season.

The few males remaining on the beach are the last remnants of the beefy guys who arrived in December. Now slim, having used up that blubber holding off less dominant male challengers and breeding females, they look deflated, mere shadows of their former selves.

The bulls will bulk up, feeding along the continental shelf for several months. They will have recovered much of their size when they return to the beach in July and August to molt.

Weaners dominate the beach, but a few females have already returned to molt. Numbers will gradually increase, until all the adult females, more than 5,000, and the thousands of juvenile seals show up in May. More seals are on the beach in May than any other time of the year.

This season’s weaners are big and fat. Some look like 2-year-old seals. Most have gone through their first molt. All elephant seals are born solid black. They molt into counter-shaded coats, dark on their backs and light on their bellies. It’s a marine camouflage that helps conceal them from predators. They melt into the dark background of the deep sea to predators above them looking down. Predators coming up from below see the lighter belly against the light of the surface.

Stranded pups are showing up almost daily on local beaches. They are tube-fed at first, to overcome dehydration and starvation. As they recover, volunteers train them to catch and eat fish. It’s not as easy as it sounds. Elephant seal pups can adapt to being fed by humans. It sounds cute, but it’s a death sentence for a seal that needs to compete in the wild. Check out this Youtube video of a Marine Mammal Center volunteer introducing a rescued pup to fish, http://bit.ly/2FYesCs.

If you find a pup on the beach, back off to a safe distance of 150 feet or so. Call TMMC in Morro Bay at 805-771-8300. The center will monitor the pup for 24 hours or more, depending on the situation and, if necessary, trained volunteers and staff will rescue it safely.

This story was originally published March 20, 2018 at 1:10 PM with the headline "Once elephant seal pups are weaned, they must learn to swim."