Sea Otters

Sea otters (Enhydra lutris) are one of the main attractions at Point Lobos, and one of the most common questions from visitors is, “Where can I see otters?”  They are the smallest marine mammals, considered by many to be the cutest by far.  However they are related to weasels and wolverines, and known to have equally unpleasant temperaments – definitely not for cuddling! 

Their main distinction from other marine mammals is their incredibly thick fur – the densest in the animal kingdom.  Estimates of the number of hairs on this animal vary, but can be as high as one million per square inch!  Comparing that with the 100,000 hairs on the fullest of human heads, it becomes almost unbelievable.  You can feel the pelt for yourself at the Information Station, but you will only be touching the outer “guard” hairs.  Under them is a layer of short hairs about 15-20 times as dense.  That is where these animals work to trap air to form a layer of insulation against the very cold water (50-55 F) where they spend most of their time.  Unlike the other marine mammals, they do not have the thick layer of blubber under the skin to insulate them.

Sea otters have something else to keep them warm – a very high metabolism fueled by the consumption of about 25% of their weight in food every day!  Sea otters are rarely seen on land at Point Lobos for a variety of reasons.  But they are well adapted to groom, eat, sleep, and socialize in the water.  (A group of sea otters is called a “raft”.)  When they sleep, they often wrap kelp over their bodies.  The kelp is attached to the rocks below and assures that they will wake up in the same place.  This trick also keeps them safe from predators and also makes them difficult for people to see when they are sleeping – be sure to bring your binoculars or borrow some at the Information Station.  Better yet, join a free docent-led walk – you can find out when they are scheduled on the calendar.


Other interesting facts about sea otters:

  • They can be 4.5 to 5.5 feet long and weigh 60 to 85 pounds, with adult males being larger.
  • They are related to about 10 species of fresh water otters around the world, like the North American river otter, which is significantly smaller.
  • They eat a wide variety of invertebrate animals, including mussels, clams, abalone and other snails, crabs, urchins, and octopus, to name a few.  But the menus of individual otters tend to be limited to 5-6 items – the prey their mothers taught them to eat.
  • They are among the relatively few tool-using animals in the world.  They carry a rock in a fold under a foreleg.  Underwater, it is used as a hammer to remove prey from the rocks, and on the surface it becomes an anvil on which to pound hard-shell animals to break them open.  Sometimes you can find them by hearing the tap-tap-tap.
  • In their mouths, they have sharp canine teeth and incisors in the front, and strong molars for crunching crab shells and the like.  You can see for yourself at the Information Station.
  • Technically, the otters at Point Lobos are southern sea otters, a separate subspecies from the northern sea otters off the coasts of Alaska and Asia as far south as Japan.
  • Otters have few natural predators, although attacks by white sharks and killer whales have been documented.  Humans hunted them for their valuable pelts from the mid-1700s until the early-1900s.  The population was believed to be 15-20,000, ranging from Baja California to the pacific northwest before they were nearly brought to extinction.  Fortunately, the fur hunters missed a few (generally thought to be less than 50) off Big Sur, and the residents of that then-isolated area kept their survival a secret until highway one was constructed between 1920 and 1940.  By then, they were protected by law.
  • Mating and birth of young occur throughout the year.  After a gestation period of 6 to 8 months, sea otters usually give birth in the water.  The mother teaches the pup everything it needs to know to survive, including finding and preparing food, and grooming the fur.  Moms still need to forage when the pups are young, and pups are left bobbing on the surface while mom is below finding food.  The pups’ thick, well-groomed fur keeps them afloat.
  • Sea otters do not migrate, but they do move around a relatively small area in search of food.  Therefore the number of otters at Point Lobos can vary between 30 and 80.
  • Point Lobos docents do a monthly count of the otters along the Reserve’s coastline, and the US Geological Survey conducts a semiannual count along their entire range from Santa Barbara’s Channel Islands to about Half Moon Bay (south of San Francisco).  The statewide count has been between 2800 and 3000 in recent years. 
  • Sea otters are listed as “threatened” on the Endangered Species Act, and strictly protected by law.  The Sea Otter Research and Conservation (SORAC) program of the Monterey Bay Aquarium watches the population very carefully and rescues sick, injured, and orphaned otters.  It also recovers dead otters and studies the causes of death.  The population has not recovered to earlier size due a number of reasons under active investigation.  You can learn more on the SORAC website.