‘Big and blubbery’ elephant seals are arriving on SLO County beaches for breeding season

A single mature bull elephant seal shifted his weight onto the sand at the Piedras Blancas rookery in mid-November.

He was the first of a couple hundred seals who will arrive at the beach north of San Simeon for the breeding season.

Docents called the bull Romeo, although he didn’t show much energy at first. He had been swimming for weeks to return from as far as Alaska.

He is taking some well-earned rest before the excitement of the females’ arrival.

Male elephant seals are big and blubbery

Romeo is nice and fat. That’s an advantage to the bulls, who fast while they are on the beach.

Recent research has shown that the bulls stop eating on their journey back to the Central Coast, and don’t start eating until they get back to Alaska in March. They go without food for about five months.

They need a hefty load of blubber to carry them through the challenges of other bulls and mate with willing females.

Pregnant females don’t usually arrive until December. After they have their pups, they nurse them for a month or so, coming into heat at the end of nursing and becoming receptive to mating again.

Mating involves a lot of barking and tail flipping, but eventually the seals get the job done. That happens in late January and February.

At least some bulls generally stay on the beach until March, when the last female leaves. That’s a long time between fish dinners.

Young seals prepare to depart

Many juvenile seals remain on the beach through December. They are on the beach for their fall haul-out, a six-week rest period.

There are more males than females at Piedras Blancas, because females mature earlier than males.

Six-year-old males are still practicing their fighting moves on each other, while females the same age are having their first, second and even third pups.

A few adult females may be on the beach. They are, for some reason, not pregnant. Whether they mate with younger bulls, or are able to mate underwater, isn’t yet known.

More than 90% of female seals have a pup every year. Those who skip a year present researchers with questions for which they have not yet found answers.

Beach transition

More adult bulls will arrive over the course of November and December.

Look for an elephant-like trunk that hangs down onto the sand when the seal is resting, with a notch across it.

Pink chest shields are another sign of maturity. Callused pink skin that extends up as far as the eyes when the seal is lying prone is typical of senior bulls.

The first pup of the season is usually born around mid-December. The birth rate increases in frequency as hundreds of females arrive and more pups are born.

Citizen science opportunity

The California Coastal Commission invites all to photograph the extent of king tides, coming up Dec. 4 and 5. The photos document high water levels, showing how sea level rise will affect the coastline.

Find the photo submission form at coastal.ca.gov/kingtides.

Check out the photos taken in previous years of San Luis Obispo beaches at https://bit.ly/3csy7fP

This story was originally published November 25, 2021 at 5:05 AM.