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.
