An elephant's prehensile trunk is a marvel of biology, featuring as many as 60,000 muscles that enable the animal to not just breathe, eat, and drink water, but also to communicate and pinch or grasp objects, among other abilities. Some elephants have been known to make rudimentary tools with their trunks to scratch themselves, repel insects, or even block roads. And one Asian elephant, named Pang Pha, in the Berlin Zoo learned how to peel a banana, according to a new paper published in the journal Current Biology—a highly unusual ability for a pachyderm, and one the other Asian elephants in the Berlin Zoo don't possess.
“We discovered a very unique behavior,” said co-author Michael Brecht of Humboldt-Universität zu Berlin’s Bernstein Center for Computational Neuroscience. “What makes Pang Pha's banana peeling so unique is a combination of factors—skillfulness, speed, individuality, and the putatively human origin—rather than a single behavioral element.”
Brecht and his co-authors first heard about Pang Pha's unusual ability from her zoo caretakers and decided to conduct a series of experiments, presenting the elephant with about 10 bananas each round and filming her behavior. The first experiments involved Pang Pha alone, and while she repeatedly raised her trunk—typical begging behavior for elephants—when approached with bananas, for the first few weeks, the elephant didn't peel any of them. Eventually the scientists realized that whether or not Pang Phase peeled a banana depended on its ripeness. She preferred to devour green or yellow bananas whole and rejected brown bananas entirely.
It was the yellow-brown bananas that Pang Pha singled out for peeling, and she was able to do it faster than most humans. First, she grasped the banana with the tip of her trunk and then broke it against the side of the distal trunk. Next, she shook the banana until the pulp fell out. She then grabbed the pulp and ate it, discarding the peel. The process continued until there was almost no pulp left inside the peel. Pang Pha made sure of that by checking several times with her trunk in case there was any lingering pulp she might have missed.
For a second round of experiments, the researchers filmed the banana-feeding behavior of Pang Pha with other elephants—namely, her daughter Anchali and another female Asian elephant named Drumbo. In that social setting, Pang Pha consumed most of the yellow-brown bananas whole instead of peeling them. But she kept the last yellow-brown banana for later and did peel that one. Neither of the other elephants peeled their bananas.
While there are random Internet videos of various elephant species also peeling bananas, the authors did not observe the behavior among the Berlin Zoo's other Asian elephants, nor among the African elephants housed in the Vienna Zoo. So where did Pang Pha learn to do it? The authors suggest it stems from her early history. She arrived at the zoo in 1987 as a baby, and her keepers partially bottle-fed her. But her primary keeper also would peel bananas in front of her and feed her the pulp, and it seems Pang Pha watched this and learned how to do it herself. Pang Pha did not pass this learned behavior down to her daughter, Anchali, however, perhaps because Pang Pha prefers to peel her bananas when she's alone.
This all suggests that elephants, in general, have unexpected cognitive abilities and manipulative skills. "Presumably human-derived complex manipulative behaviors like this were unknown in elephants or, to our knowledge, most other species," the authors concluded. "Our case study on Pang Pha's banana peeling provides insights about elephant manipulation and cognition not available from other, conventional routes of investigation."
Listing image by Kaufmann et al., 2023/Current Biology