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  • As a breeze blows through the savannah,

  • a snake-shaped tube stretches into the air and scans the horizon like a periscope.

  • But it's not seeingit's sniffing for odors

  • like the scent of a watering hole or the musk of a dangerous predator.

  • The trunk's owner is a young African elephant.

  • At only 8 years old, she still has a lot to learn about her home.

  • Fortunately, she's not alone.

  • Elephants are extremely social creatures,

  • with females living in tight-knit herds led by a single matriarch.

  • And every member of the group has one of the most versatile tools

  • in the savannah to help them get by.

  • Today her herd is looking for water.

  • Or, more accurately, smelling for water.

  • Elephants have more genes devoted to smell than any other creature,

  • making them the best sniffers in the animal kingdom.

  • Even at our elephant's young age, her trunk is already 1.5 meters long

  • and contains five times as many olfactory receptors as a human nose,

  • allowing her to smell standing water several kilometers away.

  • And now, the matriarch uses her own keen sense of smell to plot the herd's course.

  • Their journey is long, so our elephant keeps her energy up

  • by snacking on the occasional patch of thick grass.

  • But this light lunch isn't just about staying fed

  • she's also looking for clues.

  • Like many other mammals,

  • vents in the roof of an elephant's mouth lead directly to the vomeronasal organ.

  • This structure can detect chemical signals left by other elephants.

  • So as the herd forages, they're also gathering information

  • about what other herds have come this way.

  • All the while, the group's adults are on the lookout for signs of other animals,

  • including potential threats.

  • Fortunately, while lions might attack a young or sickly elephant,

  • few are foolish enough to take on a healthy adult.

  • Weighing 3 tons and bearing powerful tusks nearly a meter long,

  • our elephant's mother is a force to be reckoned with.

  • Her dexterous trunk doubles as a powerful, flexible arm.

  • Containing no bones and an estimated 40,000 muscles,

  • these agile appendages can bend, twist, contract, and expand.

  • At 8 years old, our elephant's trunk is already strong enough

  • to move small fallen trees,

  • while finger-like extensions allow for delicate maneuvers like wiping her eye.

  • She can even grab a nearby branch,

  • break it to just the right length, and wave off pesky insects.

  • Suddenly, the matriarch stops their march and sniffs the air.

  • Using smell alone, elephants can recognize each member of their herd,

  • and their exceptional memories can retain the smells of elephants

  • outside their herd as well.

  • It's one of these old but familiar odors that's caught the matriarch's attention.

  • She bellows into the air,

  • sending out a sound wave that rings across the savannah.

  • But it travels even further through the earth as infrasonic rumbles.

  • Elephants up to 10 kilometers away can receive these rumbles with their feet.

  • If the matriarch's nose is right, her herd should expect a response.

  • Smelling the secretions from her daughter's temporal glands,

  • our elephant's mother can sense her daughter's unease

  • about this unfamiliar encounter.

  • As the herd of unknown elephants approaches,

  • trunks from both herds rise into the air, sounding trumpets of alarm.

  • But upon recognition, apprehension quickly gives way to happy rumbles.

  • Members from each herd recognize each other despite time apart,

  • and many investigate each other's mouths with their trunks

  • to smell what their counterparts have been eating.

  • With the reunion now in full swing, both herds head toward their final destination:

  • the long-awaited watering hole.

  • Here, older elephants suck up to 8 liters of water into their trunks

  • before spraying the contents on themselves to cool off.

  • Meanwhile, our young elephant plays in the mud with her peers,

  • digging into the muck and even using her trunk as a snorkel

  • to breathe while submerged.

  • The pair of matriarchs look contentedly on their herds,

  • before turning their trunks to the horizon once more.

As a breeze blows through the savannah,

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B2 TED-Ed elephant herd trunk smell savannah

The secret signals elephants use to communicate - Chase LaDue and Bruce A. Schulte

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    林宜悉 posted on 2021/03/15
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