The best nose in the animal kingdom - Chase LaDue & Bruce A. Schulte

274,716 views ・ 2021-03-15

TED-Ed


Please double-click on the English subtitles below to play the video.

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As a breeze blows through the savannah,
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a snake-shaped tube stretches into the air and scans the horizon like a periscope.
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But it’s not seeing— it’s sniffing for odors
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like the scent of a watering hole or the musk of a dangerous predator.
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The trunk’s owner is a young African elephant.
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At only 8 years old, she still has a lot to learn about her home.
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Fortunately, she’s not alone.
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Elephants are extremely social creatures,
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with females living in tight-knit herds led by a single matriarch.
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And every member of the group has one of the most versatile tools
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in the savannah to help them get by.
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Today her herd is looking for water.
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Or, more accurately, smelling for water.
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Elephants have more genes devoted to smell than any other creature,
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making them the best sniffers in the animal kingdom.
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Even at our elephant’s young age, her trunk is already 1.5 meters long
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and contains five times as many olfactory receptors as a human nose,
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allowing her to smell standing water several kilometers away.
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And now, the matriarch uses her own keen sense of smell to plot the herd’s course.
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Their journey is long, so our elephant keeps her energy up
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by snacking on the occasional patch of thick grass.
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But this light lunch isn’t just about staying fed—
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she’s also looking for clues.
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Like many other mammals,
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vents in the roof of an elephant’s mouth lead directly to the vomeronasal organ.
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This structure can detect chemical signals left by other elephants.
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So as the herd forages, they’re also gathering information
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about what other herds have come this way.
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All the while, the group’s adults are on the lookout for signs of other animals,
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including potential threats.
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Fortunately, while lions might attack a young or sickly elephant,
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few are foolish enough to take on a healthy adult.
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Weighing 3 tons and bearing powerful tusks nearly a meter long,
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our elephant’s mother is a force to be reckoned with.
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Her dexterous trunk doubles as a powerful, flexible arm.
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Containing no bones and an estimated 40,000 muscles,
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these agile appendages can bend, twist, contract, and expand.
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At 8 years old, our elephant’s trunk is already strong enough
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to move small fallen trees,
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while finger-like extensions allow for delicate maneuvers like wiping her eye.
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She can even grab a nearby branch,
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break it to just the right length, and wave off pesky insects.
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Suddenly, the matriarch stops their march and sniffs the air.
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Using smell alone, elephants can recognize each member of their herd,
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and their exceptional memories can retain the smells of elephants
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outside their herd as well.
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It’s one of these old but familiar odors that’s caught the matriarch’s attention.
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She bellows into the air,
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sending out a sound wave that rings across the savannah.
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But it travels even further through the earth as infrasonic rumbles.
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Elephants up to 10 kilometers away can receive these rumbles with their feet.
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If the matriarch’s nose is right, her herd should expect a response.
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Smelling the secretions from her daughter’s temporal glands,
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our elephant’s mother can sense her daughter’s unease
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about this unfamiliar encounter.
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As the herd of unknown elephants approaches,
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trunks from both herds rise into the air, sounding trumpets of alarm.
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But upon recognition, apprehension quickly gives way to happy rumbles.
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Members from each herd recognize each other despite time apart,
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and many investigate each other’s mouths with their trunks
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to smell what their counterparts have been eating.
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With the reunion now in full swing, both herds head toward their final destination:
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the long-awaited watering hole.
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Here, older elephants suck up to 8 liters of water into their trunks
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before spraying the contents on themselves to cool off.
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Meanwhile, our young elephant plays in the mud with her peers,
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digging into the muck and even using her trunk as a snorkel
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to breathe while submerged.
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The pair of matriarchs look contentedly on their herds,
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before turning their trunks to the horizon once more.
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