Harboring a Soft Spot for The Harbor Seal

I also have a soft spot for harbor seals. Their teardrop shaped bodies are adorably plump and those big round eyes make them seem shy and gentle. Like dolphins, they always appear to be smiling.

Seals, seal lions and walruses are members of the infraorder Pinnipedia, which is Latin for “wing foot” or “fin foot.” Harbor seals have two pairs of flippers. The short foreflippers are used for navigation and to hold food. The larger back flippers, which move side to side, provide locomotion.

There are more than 30 species of pinnipeds worldwide, four of which live in the Channel Islands National Park and Marine Sanctuary. These include Pacific harbor seals (one of five subspecies of harbor seals), California sea lions, northern fur seals and northern elephant seals.

It really isn’t hard to tell sea lions and harbor seals apart if you remember that “sea lions have ears,” while harbor seals, which are true seals, have no external ear flaps. Also, harbor seals have round heads, while those of sea lions look more like a dog’s. Making identification even easier is the harbor seal’s quirky habit of balancing on just a small part of its anatomy, achieving a banana-like shape. It doesn’t seem possible that an animal five to six feet long and weighing more than 300 pounds could do this so easily (and not topple off rocky pinnacles while asleep) but harbor seals do and they are often so motionless that they are sometimes initially mistaken for part of the terrain.

Unlike California sea lions, Pacific harbor seal males do not have harems or fight over territory or females. Instead, they form mating couples, though a female may mate with other males as well. Unlike many other sea creatures (sharks and sea otters for example), it is the female who leaves bite marks on her mate, not the reverse. Through delayed implantation, the females mate in the water and give birth at the same time every year. Gestation takes nine months and the two to three foot long pups are born on the shore. Mothers care for and nurse their pups for only four to six weeks, during which time the pups gain about 25 pounds. They are able to swim only minutes after birth and can dive for brief periods when they are only two or three days old.

Adult harbor seals can hold their breath for as much as half an hour and have been known to dive as deep as 600 feet. Pinniped nostrils are locked closed to prevent water entry and the animals must snort to open them.

Female harbor seals can live for 35 years, males for 25. They eat fish, octopus, squid and a variety of shellfish. They are preyed upon by killer whales, sharks and, in some areas of the world, humans.

Wikipedia says there are approximately 350,000 to 500,000 harbor seals worldwide. As I already mentioned, there are five subspecies of harbor seals. Those found off our coast from Alaska to Baja are Pacific harbor seals, Phoca vitulina richardii.

Harbor seals in U.S. waters are covered by the Marine Mammal Protection Act. Populations on both our East and West Coasts are stable except for the Gulf of Alaska, where numbers are low compared to historical highs and may be declining.

While sea lions love to play a game of “chicken,” speeding toward divers/snorkelers then turning away and barking at the last minute, harbor seals play a gentle game of hide and seek among the kelp on the bottom. If you ignore one, it may get braver, coming so close you have to acknowledge it.

Wherever they are, California sea lions make their presence known with a lot of raucous, gratuitous barking; harbor seals are much less vocal.