Cambrian: Opinion

First of the big elephant seals return to Piedras Blancas

There are some large seals on the beaches at the Piedras Blancas elephant seal viewing site. These are what we call subadult males (SAMs), the equivalent of late adolescents. They act big, vocalizing and stretching their necks upward to gain height. Visitors ask what their sounds mean.

“They’re saying, ‘I’m big and I’m a boy,” I tell them.

These guys like to spar and playfight, but rarely draw blood. A SAM  chooses his playmates carefully, refusing to spar with a seal bigger than himself.

They are fun to watch, but in late November docent guides are often looking seaward watching for the huge adult males to arrive. The first one came in last week, a bit early, but there was no doubt about who he was because he was so much larger than the others on the beach.

After bulking up in the North Pacific, foraging for deep dwelling creatures, usually in the Aleutian Islands in Alaska, the males have put on enough weight to survive over three months of fasting during the birthing and breeding season here. These big guys, alpha males and wannabe alpha males, can get up to 5,000 pounds and be 15 or 16 feet long.

Their arrival, one by one, as they try to claim a territory on the beach, heralds the beginning of the most exciting time of year at the rookery. As he comes in, he usually collapses on the sand, heavy as he hits gravity after being buoyant and nearly weightless for months in the sea. He may relax for days, or maybe only hours before a rival arrives.

His voice is his first attempt to establish dominance. It’s a big sound —someone has described it as sounding like a Harley revving up in a gym. That may be all it takes for one of the guys to back off and look for another spot on the beach. But if they seem to think that they are about the same size with the same impressive voice, they may fight.

I recently read an article that described research into the vocalizations of the adult males. Researchers set up a speaker on the beach to broadcast a recording of an alpha male. A big seal approached the speaker, the speaker  made its sound, and the seal turned and retreated. Soon another male came in, the speaker made the same sound, and the seal went over and knocked it over.

There are many confrontations as the males try to establish their territories. The pregnant females begin arriving in December and each alpha male will have a harem of 30, 40 or more females. The first pup is usually born around Dec. 15 or 20 and births continue through January. The mother nurses her pup for a month and is ready to mate again.

That’s what all the male rivalry is about. Each alpha expects to mate with all the females in his harem, and he chases away the males that try to sneak in.

With a sigh of relief, and thanks to the Coastal Commission’s denial of proposed seismic testing, we watch the season begin unthreatened by the human actions that might have interrupted it.