Fall is “R & R” (rest and relaxation) time for young elephant seals. Juveniles arrive on the beach at the Piedras Blancas viewing site in what we call the fall “haul out.” There may be a few of January’s youngsters in the mix, but most of them are between 2 and 6 years old. In the past week more and more young seals have come in to rest, but they are still filling up the beach at the north end of the parking lot rather than the larger beach on the south end.
Although they travel alone on their migration journeys, each one knows when to take a vacation from the sea and where to go to do it. Elephant seals are a good example of Mother Nature’s ability to hardwire creatures to operate on instinct. The elephant seal calendar is a round-robin cycle of different ages and genders that come in during different months to birth, breed, molt and rest. It’s the same every year. This is resting time.
Elephant seals alternately feast and fast. They feast at sea, navigating their routes in the north Pacific to feed for months, returning to the rookery, where they don’t eat at all — this time of year for about a month.
Why do these young seals come in during the fall haul out, as they aren’t breeding, birthing or molting? One theory was that after months in the sea, where they are buoyant, that, like astronauts, they would lose bone mass. Hitting the beach and gravity might be necessary to rebuild their bones. Researchers performed MRI tests on some of the seals when they first came in and a month later, just before they set out to sea again, and discovered that they do gain bone mass while they are ashore.
Another theory is that the fall journey helps them to get into the migration pattern they will follow when they are older and will return to California in the winter for birthing and breeding.
These juvenile seals play a bit, the young males sometimes sparring in the water, but most of the time they snooze in the sun. The sparring is one way to tell the males from the females at this stage. It’s not as easy to tell them apart from their faces as it is when they are adults, when the males have the trunk-like proboscis that gives elephant seals their name.
They don’t start to get it until they are about 5 years old. Then it grows longer each year until they are mature. Its length is one way to estimate how old they are. The females don’t get the big nose. Some of the males that are here now are just starting to get it, at first with pointy, ratlike noses which broaden out and get longer as they get older.
More juveniles will come in next month and, as they leave, subadult males will haul out. Near the end of November the huge adult males will begin arriving to set up their territories for the birthing and breeding season.