Pup season

It’s that time of year, the elephant seal birth and breeding season. The first pup was born at Piedras Blancas December 11. Expect daily births through the beginning of 2021.

The elephant seal viewing areas is open, but keep in mind Covid safety measures: wear a mask, stay six feet from other visitors. Check out the Friends of the Elephant Seal live beach cam, https://elephantseal.org/live-view/, or the FES Facebook page.

Maternity ward

The first pup was born in a section of the south section of the elephant seal viewpoint that has become a center for early births, hence the Maternity Ward nickname. Pups can be born anywhere on the beach, throughout the rookery, from the lighthouse station to Arroyo Laguna.

Pups are about three feet long and weight about 75 pounds when they’re born. They soon plump up on their mothers’ nourishing milk. They’ll nurse for a month. The mothers then wean them, breed, and return to the ocean.

Bulls vie for dominance

Dominance dictates the social organization on the beach. A single bull will be surrounded by 20 or 30 females and their pups. As the beachmaster, he needs to be vigilant, because less dominant bulls will constantly attempt to sneak into the harem of females, or make a direct challenge.

Bulls have unique calls that other bulls recognize. Research has shown that bulls avoid those that have won earlier confrontations. They are more willing to fight bulls with whom they are more evenly matched.

Watch as one bull trumpets his challenge. See which bulls respond – bulls up and down the beach take notice of every call. One may only raise his head, but another may take up the battle.

 If a beachmaster leaves his central position to fight, another bull may take his chance to move in.

Size is significant, but it’s not the sole factor in determining dominance. Look for the length of the nose and the size of the pink chest shield. Both continue to grow from puberty throughout a seal’s life, so they indicate age and seniority.

No food for seals

Because the adult seals don’t eat while they are on the beach, they lose a lot of weight. Nursing mothers may lose a third of their body weight in that month. Bulls may be on the beach as long as 100 days, going from their biggest bulk at the beginning of the season to slender shadows of their former selves by March.  

The seals need to conserve every ounce, until they can get back to the ocean and hunt fish and squid again. The mothers need their blubber to metabolize into milk for their pups. The bulls need it to remain dominant until after the pups are weaned, when the females come into estrus and are willing to breed.

That dominance hierarchy reduces the need for each beachmaster to fight every challenging bull. Fighting uses a lot of energy, so the reproduction advantage goes to the bull who can keep himself vigorous longer, and breed more females.

It’s a balance. Watch the seals jockey for dominance and survival in this winter season on the beach.