Sea Otter (Enhydra lutris)
Order: Carnivora, Family: Mustelidae
Male sea otters average 5 feet and 70 pounds; females average 4 feet and 60 pounds.
They are dark brown with lighter heads that turn grayish white with age.
Sea Otters live in shallow coastal waters, especially kelp beds.
II. GEOGRAPHICAL RANGE AND HABITAT:
- Male sea otters average 5 feet and 70 pounds; females average 4 feet and 60 pounds.
- They are dark brown with lighter heads that turn grayish white with age.
- Sea Otters live in shallow coastal waters, especially kelp beds.
- They range from central California north to Prince William Sound, Alaska, and westward along the Aleutian, Commander and Kuril islands. They can also be on the southern tip of Siberia's Kamchatka Peninsula, and the southeastern coast of Sakhalin Island.
IV. LIFE CYCLE/SOCIAL STRUCTURE:
- Carnivores, sea otters prey on bottom-dwelling invertebrate species such as abalone, urchins, clams and crabs. They are expert divers.
- Highly intelligent, otters use rocks for cracking shells as they float on their backs while feeding.
- They spend about eight hours a day diving and eating.
V. SPECIAL NOTES/ADAPTATIONS:
- Male sea otters live for 10 to 15 years, and females for 15 to 20.
- Female otters reach sexual maturity at 3 or 4 years of age; however, it is unclear exactly when males become capable of breeding.
- Sea otters reproduce throughout the year, but most mating occurs from October to November. Gestations lasts five or six months, with the majority of births occurring between late May and June.
- Social animals, sea otters live in family groups.
- The female otter has a very strong maternal instinct, and seldom leaves her pup except when diving for food. When traveling, sleeping or grooming, the mother usually carries the pup on her chest as she floats on her back.
- Bald eagles prey on newborn otters, and killer whales may take a few adults.
- A layer of air trapped in the sea otter's fur keeps its skin dry and insulates the otter from cold water.
- Grooming is extremely important for otters, since dirty, oily fur allows water to penetrate to an otter's skin, which could potentially cause hypothermia and death. As a precaution, otters twist, roll and dive after eating to clean their fur.
- To get air in their fur, otters float belly down, blowing bubbles and rubbing them into the fur.
- Sometimes sea otters hold hands while sleeping, so they don't float away from each other. They will also wrap kelp around themselves to prevent getting washed into shore.
- Descended from river otters, sea otters are larger and are never seen in freshwater rivers or lakes.
- Once hunted almost to extinction for their thick, lustrous coats, sea otters are no longer threatened. As their numbers increase, however, their food supplies become more strained. Many of the shellfish essential to the sea lion's diet, such as the abalone and crabs, are also economically important to humans.
- Extremely resourceful and intelligent, sea otters are the only mammals other than primates to use tools. They also demonstrate a remarkable ability to adapt to their environment. For example, otters have discovered that discarded aluminum cans on the sea floor often contain small octopuses. One otter was seen gathering eight cans in 15 minutes, with five cans housing octopuses.