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  • Here’s one word to describe the Northern California coast: COLD.

  • If you or I were in those waves without a wetsuit right now, we’d get hypothermia in minutes.

  • But sea otters have figured out how to survive here.

  • Which is amazing, especially when you consider that this little guy has to maintain an internal body

  • temperature around 100 degrees Fahrenheit.

  • Almost twice as warm as the water he’s swimming in.

  • Sure, whales do it. Sea lions do it. But those mammals have had tens of millions of years

  • to adapt to life in the ocean.

  • Evolutionarily speaking, sea otters are newcomers... land animals that waded into the ocean a mere

  • couple of million years ago.

  • Unlike other ocean mammals, they have no blubber.

  • And theyre small, meaning they are constantly losing heat.

  • Their ace in the hole-- is fur.

  • Sea otters have the thickest fur on the planet. Up to a million hairs per square inch.

  • It’s what keeps them alive.

  • It also almost killed them -- back around the 19th century sea otters were hunted nearly

  • to extinction to make hats and coats.

  • But it’s not really the fur, per se, that keeps the otter warm. It’s air.

  • Fur works by trapping air near the skin’s surface, like a down comforter.

  • Sea otter fur is so dense it’s basically waterproof. You can see how dry it is close

  • to the skin.

  • That layer of air gives the otter’s fur a glossy look as it tumbles

  • through the water.

  • Baby sea otters? Their fur traps so much air that they bob at the surface -- their

  • fluffiness makes them buoyant. That is, until they shed the pup fur and learn to dive.

  • This excellent insulation comes at a price.

  • Every time a sea otter dives, some of the air in their fur gets forced out -- see those

  • bubbles? And so the otter has to groom himself all over again, to pump more air in.

  • Let’s take a closer look at this fur.

  • As you can see, sea otter fur is actually made up of two kinds of hair: under fur, the

  • insulating part, and those longer, protective guard hairs.

  • Under a microscope, you can see how the individual hairs are scaly and rough.

  • That roughness is important.

  • Those barbs on the hair shafts let the fur mat together.

  • That’s what traps the air in.

  • For comparison - here’s a coyote. Coyotes, of course, don’t live in the freezing ocean,

  • and their hairs don’t have the barbs.

  • Their fur keeps them warm on land, but they wouldn’t stay dry in the ocean.

  • In a lot of ways, otters have more in common with land animals.

  • But many years ago, otters took an evolutionary leap into these icy waters.

  • And today theyre making it work.

Here’s one word to describe the Northern California coast: COLD.

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