Elephant seal pups are back on the beach at Piedras Blancas
Seal mothers are early this year. Pups arrived on the beach at Piedras Blancas before the adult males had sorted out their dominance hierarchy. The early births are unusual, but not unknown.
The usual sequence of events for these migratory seals is that the adult males return to the beach starting around Thanksgiving. They spend the next month jockeying for position, threatening, trumpeting, chest bumping and even fighting to determine who is the baddest bull on the beach. This is really important, because the alpha bulls are the ones that get breeding rights. The also-rans have to take their chances at the edges of the harem.
Pregnant females usually begin arriving in mid-December, then continue to arrive through January and February, their numbers eventually swelling to more than 5,000. They give birth to their pups within a few days. So if you’re patient, chances are good you will see a pup born. Bring a chair and a snack and settle in.
This year, the first pup was born on the south portion of the beach, easily seen from the boardwalk. The second mother joined her and had her pup a week later. Several females parked themselves in the same general area, a maternity ward of sorts. Look for a seal digging herself into the sand, or squirming uncomfortably. That may — or may not — indicate an imminent birth. Visitors want to know which seal will give birth next, but there’s no sure way to know.
Whether the early date reflects the predicted El Niño or the influence of ocean changes such as the warm-water blob that fostered a toxic algae bloom can’t be determined yet. U.S. Geological Survey biologist Brian Hatfield, who monitors the elephant seal population, said when seals started coming to Piedras Blancas in the 1990s, births were in February. They gradually got earlier until about 10 years ago. Since then, the first birth is usually in December.
He remembered one seal who returned to the same part of the beach every year for four years to be the first mother of the year. He identified her by her cloudy eyes, even though she wasn’t tagged.
“I think she was blind,” he said.
Apparently it didn’t slow her down. Elephant seals hunt at 1,000 feet and deeper, where there is almost no light, although it’s normal for seals to have good vision in low light conditions. Some of their prey, such as Humboldt squid, is bioluminescent.
The pups nurse for a month. Note how fast they grow. Newborns are skinny black critters, but they begin to fill out as soon as they start consuming that high-fat milk. Seal mothers don’t eat during their time on the beach. They have to create that milk by metabolizing their blubber. They may lose as much as 20 pounds a day, while the pup gains 10.
Pups can’t swim when they are born. If tides are high enough to reach them on the beach, they can be swept away and drown. Recent tides have been exceptionally high, with more “king tides” predicted before Christmas. Cross your fingers that they are born out of harm’s way.
Christine Heinrichs’ monthly column is special to The Cambrian.
This story was originally published December 22, 2015 at 3:29 PM with the headline "Elephant seal pups are back on the beach at Piedras Blancas."