Cambrian: Opinion

Welcome back, kids! Juvenile seals return to Piedras Blancas

This juvenile shares beach space with a mature bull. The bull is still molting his skin but will soon leave on his next migration.
This juvenile shares beach space with a mature bull. The bull is still molting his skin but will soon leave on his next migration. Special to The Cambrian

Small seals are joining the big, mature bulls on the beach at Piedras Blancas in August. It’s time for the adults to move back into the ocean and youngsters to surf in.

As different as they look, they are all the same species. Young male seals don’t have that distinctive trunk-like nose, and females never grow one. The males start growing their nose when they are about 5.

The bulls need to shove off and get back to bulking up. Their food is north, along the Canada and Alaska coasts. They will need every pound of blubber to live on during the breeding season. While they are on the beach from December through February, they don’t eat. So they need plenty of blubber for the rigors of battle for dominance and overseeing the harem.

The fall months of September, October and November are the Juvenile Haul-Out. Young seals, mostly less than 5 years old, get the beach to themselves. They are resting and gaining strength. The smallest are the young of the year, the pups born in January and February. They return in the fall from their first migration.

Females mature sooner than males. By age 5, most females are already mothers. Males are just going through puberty at age 5.

Only about half of those born make it back, the rest lost to predation and starvation. It’s a tough world out there. These youngsters are able to dive as deep as 4,000 feet, even in their first year. With no guidance, they find their way north and learn to hunt fish and squid along Canada’s west coast. Some get as far north as the Aleutians, where the adult males feed.

Their bellies are light, their backs dark. It’s countershading, a form of camouflage to help them escape the notice of predators. Great white sharks and orcas swimming above them look down at their dark backs, blending into the ocean depths. From below, they see the light belly against the bright surface. In the ever-changing play of light and dark, any advantage helps.

All those young males on the beach together inevitably spar with one another. It’s not the serious fighting of the adult bulls in mating season, but they are getting ready. Working out with their brothers also helps their bones grow stronger. The ocean supports them during their five-month migration, and their bones lose density. Their muscles get stronger, too, from the exercise and supporting their weight under the pressure of gravity.

The young seals don’t eat during their fall haul-out. Their metabolism allows them to draw on their blubber to meet all their needs on land.

Juvenile seals are often active during their fall haul-out. Visitors see them sparring in the water and on the sand. Young females don’t fight like that, but they can be cranky, barking at one another. Or one might toss a bit of kelp around playfully.

Every day is different. When visitors ask me when the best time to view the seals is, I tell them,

“Today!” You’re here on the best possible day. The seals never disappoint.

Christine Heinrichs’ column appears the fourth Thursday of each month and is special to The Cambrian.

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