This is scientific American 60 second science.

I'm Christopher Intagiyata.

Sea otters are pretty petite compared to other marine mammals,

which means that despite their furry coats, they tend to lose heat quickly, and they

need lots of energy to stay warm.

So they need to eat about 25% of their body weight every day.

Sarah McKay's trouble, a sensory ecologist at UC Santa Cruz.

So we know they have to eat that much, but in order to eat that much food, that means that

the otters have to find all of that food, and that's where we come in.

She and her team analyzed the otters senses to solve the

mystery of how they're such efficient foragers. Vision isn't reliable, she

says. It's pretty dark and murky underwater and crabs and clams tend to hide.

Hearing is also tough for otters in the noisy underwater environment and

sniffing is no good either.

When they're underwater they're holding their breath.

But what's left is touch.

So Strobel and her team measured the sensitivity of Otter's paws and whiskers.

They blindfolded an otter named Selka and then presented her with plastic plates, engraved with tiny grooves, kind of like corduroy.

Selka's job was to choose the plate with 2mm grooves, which she'd been trained to associate with a tasty shrimp,

instead of plates with differently sized grooves.

Turns out Selka could perceive just a quarter millimeter difference in the grooves width with

her paws, above and below water, and half a millimeter difference with her whiskers.

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