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I would like to know the evolution of an otter. What other species are they related to? Who did they originate from? Who were there ancestors?

Sea otters are the most recently evolved marine mammal. It is believed that they originated from river otter stock or ancestors approximately 5-7 million years ago. Sea otters are in the weasel or mustelid family. Other members of that family include badgers, polecats, skunks, wolverines, martens, weasels, fishers, sables, and river otters.

Can you please give me some reasons why Southern sea otters need to be protected?

Sea otters are what biologists refer to as a keystone species as well as an indicator species. Keystone species have a disproportionately large effect on their ecosystem. For example, when sea otters were almost exterminated by the fur trade, a shift in the ecosystem took place. In the absence of sea otters, the invertebrate kelp grazers they feed on, such as sea urchins, proliferated and destroyed the kelp forests. When sea otters were almost gone, so were the kelp forests. A indicator species is monitored by scientists to get a general indication of the health of the ecosystem in which it lives. When an indicator species population is doing well, that is a sign that the ecosystem is healthy. Southern sea otters began dying in 1995 from a disease that was associated with the prey they eat. This tells us that we better pay attention to what is happening to sea otters. If they're dying from disease associated with what they are eating, and humans eat many of the same items, we need to watch for similar health problems in people.

Sea Otters are my favorite animal, can you tell me what I can do to help them and learn more about them?

For more information about sea otters, please visit:

www.defenders.org/defenders/kidsplanet/factsheets/otter.html

www.kidsplanet.org/tt/seaotter/home.html

www.defenders.org/wildlife/new/seaotters.html

In general, sea otter populations are not doing that well in California (disease, entrapment in fisheries gear, habitat degradation, food limitations) and Alaska (orca, or killer whale, predation-- possibly other reasons such as pollution are responsible).

Sea otters need help from as many people as possible! Keep posted and inform others about the plight of sea otters worldwide . Write letters to your congressional representatives telling them how much you care about sea otters, how important they are for the ocean and that you'd like to see efforts move forward to recover declining sea otter populations. You could organize a sea otter festival at your school too.

How is the California sea otter different than the Alaska sea otter?

The California sea otter, or southern sea otter, and the Alaskan sea otter, or northern sea otter, are genetically distinct subspecies. Besides this genetic difference there are some behavioral and physical differences. The Alaskan sea otter can be slightly larger than California sea otters. The Alaskan sea otters eat more fish and haul out on land more often than do the California sea otters. And, finally, it has been observed that raft sizes in Alaska can sometimes include hundreds of animals. In California, these raft sizes are considerably smaller.

How do sea otters protect themselves? What are their predators?

Sea otters have three basic ways to escape predators: fleeing; taking refuge in the kelp where they live; and coming up on land. They also have strong teeth they can use in interactions with other sea otters. Great white sharks are the primary predator in California. Studies in Alaska recently showed that orcas (killer whales) are eating more and more sea otters in that region, possibly because the usual prey (seals and sea lions) are in decline. Other factors that may be influencing the orcas to eat more sea otters may include natural disturbances to the ecosystem that occur over space and time, as well as overfishing. Other reported predators that feed on sea otters include stellar sea lions, coyotes, bears and eagles.

Where do sea otters give birth? 
On land or in water for the southern, or California, sea otter.

How do sea otters give birth? 
Like all mammals, they give birth to live young. Otter babies are called pups.

When do sea otters give birth and how many pups are born? 
Sea otters generally give birth to one pup a year. If they give birth to two, they will abandon one of them, as they can't care for two at a time. This is how pups are orphaned. Orphans rescued by trained wildlife rehabilitators can survive to adulthood and, in fact, all three otters at the Monterey Bay Aquarium were orphans. Otters are full-grown at about 3 years of age and generally they are weaned between 6 months and 1 year of age.

Sea Otters

How big are pups when they are born? 
3-5 lbs.

How do they grow? 
Through drinking the very fat, rich milk that the mother provides for the first two months of the pupsí life. Solid food is gradually worked into the pupsí diet as they mature.

How do sea otters communicate?
Through body contact, nosing one another, head-jerking and vocalizations. Sea otters, in comparison to sea lions, for example, are not extremely vocal animals. However, adults use a soft, low cooing sound, and grunts to exhibit "contentedness," among other things. Pups use a high-pitch squeal to communicate with their mom. Some other sounds in the vocal repertoire of sea otters include whistles, whimpers, squeaks, whines, growls, snarls and hisses.

How are sea otters listed under the Endangered Species Act? 
The southern sea otter is listed as "threatened." If the population decline continues, this listing could be changed to "endangered." The northern sea otter, which consists of sub-populations in Alaska, Canada and Washington, isnít listed as a whole subspecies. The different sub-populations have different status classifications. Currently there is no federal or state Endangered Species Act listing for Alaska and Canada. There are petitions and threatened lawsuits to force U.S. Fish and Wildlife Service to list certain otter populations in the central Aleutian chain in Alaska. Washington has listed the sea otter as endangered.

What other protections are afforded to sea otters? 
All sea otters are classified as "depleted" under the federal Marine Mammal Protection Act. The California sea otter is also listed under state law as a "fully protected mammal."

What do sea otters eat? 
Abalone, squid, snails and other molluscs; clams; mussels; crabs; lobster; urchins; sea stars; sea cucumbers; chitons; marine worms; and about 40 other marine invertebrates; and on occasion, marine birds; and in Alaska, certain fish.

Sea Otters

How do sea otters forage for food? 
Sea otters generally do not spend more than two or three minutes diving for food. They use their sensitive paws, whiskers and vision to make their way through the water to find food. Sea otters then return to the surface with their prey, lie on their backs, place the food on their chests and break open the prey using a tool of some kind (rock, bottle, etc.).

Where are sea otters on the food chain?
Sea otters are considered to be "opportunistic feeders" Ė that is, they feed on many prey items. They are carnivores, and, at times, omnivorous, meaning they feed on both animal and plant food. They are the top-end predator in the nearshore marine ecosystem.

What are the natural predators of sea otters? 
Great white sharks are the primary predator in California. Ongoing studies in Alaska recently revealed that orcas (killer whales) are eating more and more sea otters in that region, possibly because the usual prey (seals and sea lions) are in decline. Other factors that may be influencing the orcas to eat more sea otters may include natural disturbances to the ecosystem that occur over space and time, as well as overfishing. Other reported predators that feed on sea otters include stellar sea lions, coyotes, bears and eagles.

How do sea otters protect themselves? 
Sea otters have three basic ways to escape predators: fleeing; taking refuge in the kelp where they live; and coming up on land. They also have strong teeth they can use in interactions with other sea otters.

What is the lifespan of a sea otter? 
Sea otter males generally live up to 10-15 years, while females live 15-20 years.

What is the habitat of a sea otter? 
Sea otters live in the nearshore marine ecosystem, which consists of rocky shores and kelp forests. In California, many sea otters spend a considerable amount of time in an estuary called Elkhorn Slough that is located near Moss Landing. A large part of their day is spent in the kelp forest and rocky areas, where much of their prey is found. And, the kelp canopy provides shelter and protection for sea otters from storms and predators.

Do sea otters have personalities, specifically with their interactions with humans? 
Sea otters are wild animals, which means their behavior towards humans can be unpredictable. Like people and other animals, they all have individual personalities. Some may be aggressive towards humans and other otters may be friendly. There have been occasional reports of sea otters messing around with divers (e.g., pulling at their dive caps and other things).

How do sea otters use their forepaws and forelegs? 
Sea otter forepaws are quite dexterous and sensitive, allowing sea otters to extract their prey from tight spots and to sense the prey they do handle. The pads of their paws are different from those of dogs -- sea otters have a continuous pad that covers the whole bottom part of the paw, while a dogís paw is not fused.

What is the size and weight of sea otters?
California sea otters average 4 feet in length and 50-60 pounds in weight. Northern sea otters are slightly larger.

What information do we know about the sea otter fur trade? 
Aboriginal people hunted sea otters for many thousands of years. Coastal North American Indians, northern Aleuts and the Japanese valued otters for their warm fur. In some areas, the Aleuts over-exploited otters and substantially reduced their populations. However, it wasn't until the mid-1700s that widespread commercial hunting of sea otters took place, leading to the near-extinction of the species. The extremely profitable sea otter fur trade began in 1741, when a shipwrecked Russian expedition led by Vitus Bering discovered sea otters on one of the Commander Islands. ("Sea Otters" by Marianne Riedmann, 1997, published by the Monterey Bay Aquarium). You can obtain more information about the fur trade from this book.

What is the range of the California Sea Otter? 
The California sea otter is found from Half Moon Bay in the north to, as of 1998, just beyond Point Conception (in Santa Barbara county) in the south.

What is the classification for sea otters?

  • Kingdom-Animalia
  • Phylum-Chordata
  • Subphylum-Vertebrata
  • Class-Mammalia
  • Order-Carnivora
  • Family-Mustelidae
  • Genus-Enhydra
  • Specific Epithet-lutris
  • Species -Enhydra lutris