Southern Sea Otters - Enhydra lutris
Hunting between 1741 and 1911 was so intense that sea otters were thought to be extinct in California. However, a remnant population of about 50 otters survived off the Big Sur coast in the early 1930's. With full protection by state and federal laws the population began to recover and expand north and south along the coast. In recent years, between 2500 and 3000 southern sea otters have been counted in a range extending from Point Conception to Pillar Point.
Having left its land and river habitat for a marine existence only three million years ago, the sea otter has not evolved to the extent that it has blubber. Instead, sea otters have the densest fur of any animal. The coat maintains its insulating properties only so long as the fur is kept scrupulously clean. A sea otter spends many hours each day grooming. A soiled sea otter can die of exposure to the cold water within just a few days.
Sea otters eat a variety of invertebrates, including mussels, clams, abalones, snails, crabs, urchins, sea stars, squid, and octopus. Otters eat many animals that graze on kelps and therefore protect the kelp from being overgrazed. Food is gathered with the forepaws and carried to the surface where the otter floats on its back and consumes the prey. Otters need to eat about 25% of their body weight each day to stay warm. They seldom come ashore and can be seen in the kelp where they rest. When sleeping, the otter may wrap itself in kelp fronds so it won't float away. Several otters may raft together in the kelp. They are not sound sleepers and are easily disturbed by any sort of noise or activity.
Male sea otters are about 5 1/2 feet long and can reach 80-85 pounds, and average 62 pounds. Female sea otters are about a foot shorter and lighter than males. Once sexually mature, female otters can pup annually. Mating occurs year-round. During mating, the male will bite the female's nose, sometimes resulting in extensive scarring of the muzzle. Look for the white scar tissue or a pink muzzle on a recently bred female. Pupping can occur anytime after a 4- to 6-month gestation period.
Pups are usually born in the water and receive round-the-clock care. Mom will carry the pup on her chest while at the surface and leave the pup floating like a cork in the water while she hunts for food. The pup will make a shrill cry calling for the mother. Pups learn to dive at 6 weeks and are weaned by the mother at 5 to 8 months.
Otters have few natural predators, although attacks by white sharks and killer whales have been documented. Humans are by far the most effective predators. Some otters are lost each year to gill net fishing and gunshot wounds. When an oil spill coats the fur, an otter is kept from effectively grooming, and the animal can die in a short time from exposure and the inhalation and ingestion of the toxic oil and fumes.