Scientists recently discovered a new elephant behavior that is simply bananas. An Asian elephant (Elephas maximus) at the Berlin Zoo can use her trunk to peel bananas before eating them, a new study reveals.
She wasn't trained to do this; instead, researchers believe she picked up the skill by watching zookeepers peel bananas for her.
An incredible video shows the elephant, named Pang Pha, first grasp the banana with the end of her trunk. Then, she twists her trunk around on itself, breaks the banana by ripping off the stem end, and throws the rest on the ground. She then picks up the banana again, this time by pinching the frayed peel with her trunk, and uses the banana's weight to methodically peel the fruit. This might not be exactly the way keepers peel bananas, but it's a remarkable feat for a thumbless animal.
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Study first author Lena Kaufmann, a doctoral student at Humboldt University of Berlin, began working with the elephant to study how the animals sense touch sensations with their trunks. Soon after, the zookeepers began to mention other intriguing behaviors they had spotted, like banana peeling. Kaufman didn't believe it at first. To see for herself, Kaufmann began to feed Pang Pha bananas to see what would happen.
"I started bringing bananas for her," Kaufmann told Live Science. "And I didn't see anything. She just took the banana and ate it. So I started doubting it."
But Kaufmann was bringing green bananas, fresh from the supermarket, and Pang Pha would simply swallow them whole. When Kaufmann offered Pang Pha a more ripe banana, one with little brown spots on the peel, the elephant grasped the banana and carefully opened it to get at the pulp inside.
It turned out that Pang Pha has preferences. She will eat green bananas whole when offered them, but will take time to peel sweeter, more ripe bananas. She does not, however, like extremely ripe bananas.
"At first, I gave her a [brown banana] and she basically dropped it and left it on the floor,” said Kaufmann. "After that, I gave her a second one, and immediately she threw it at me."
Through repeated experimentation, Kaufmann learned that Pang Pha will occasionally peel and eat an overripe banana, but she clearly doesn't seem to enjoy them.
Kaufmann next studied how and when she peels bananas in social situations, where she is being fed bananas as a part of a group. In these cases the vast majority of Pang Pha's bananas were eaten without being peeled. That is, until she was on her last banana, which she would take her time to peel 60% of the time.
Kaufmann believes that Pang Pha's reluctance to peel bananas during group feeding is a sign that she optimized the behavior for her benefit. When alone, Pang Pha is more likely to carefully peel each banana, but when eating communally, she has to eat very quickly, or the other elephants might leave her with no bananas. In that case, she swallows them whole, but chooses to savor the last banana.
Pang Pha's remarkable feat was described April 10 in the journal Current Biology.
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Cameron Duke is a contributing writer for Live Science who mainly covers life sciences. He also writes for New Scientist as well as MinuteEarth and Discovery's Curiosity Daily Podcast. He holds a master's degree in animal behavior from Western Carolina University and is an adjunct instructor at the University of Northern Colorado, teaching biology.