Scientists say an Asian elephant at a South Korean zoo can imitate human speech, saying five Korean words that are readily understood by people who speak the language.
The male elephant, named Koshik, invented an unusual method of sound production that involves putting his trunk in his mouth and manipulating his vocal tract.
"This is not the kind of sound that Asian elephants normally make, and it's a dead-on match of the speech of his trainers," says Tecumseh Fitch of the University of Vienna in Austria.
Many birds are excellent vocal mimics, but this isn't common among mammals.
Humans can do it, of course but our closest primate relatives can't. Dolphins, whales and seals are known to imitate sounds. Dolphins can mimic weird computer-generated noises, for example, and one seal named Hoover famously learned to say phrases like "hello there" after being raised by a Maine fisherman.
And scientists already knew that elephants have some ability to mimic what they hear. In 2005, researchers reported on a female African elephant that made truck sounds and a male African elephant that learned to chirp like the Asian elephants he lived with at a zoo.
What Koshik can do goes way beyond what's been heard from elephants before. Videos show him putting his trunk in his mouth and saying "annyong" ("hello"), "anja" ("sit down"), "aniya" ("no"), "nuo" ("lie down") and "choah" ("good") all words he presumably picked up from his trainers.
Scientists saw these videos on You Tube and didn't know what to think. "There had been always the question, 'Is this true, or is it a fake?' No one really believed it," says Angela Stoeger, also at the University of Vienna. She and her colleagues went to check it out.
Their study, in the journal Current Biology, shows that Koshik is the real deal. The researchers compared his utterances with normal Asian elephant sounds and showed that he clearly was not just making some elephant noise that was being interpreted by onlookers as human speech.
"There is no way this is just some sort of accidental thing, that the elephant was making normal elephant sounds and somehow got rewarded for doing it and then people started saying, 'Oh, he's a talking elephant,' " says Fitch. "That's what I think makes it really convincing that this is speech mimicry."
What's more, the researchers asked native Korean speakers to listen to the sounds made by Koshik and transcribe what they heard. While most listeners agreed on the vowel sounds, there was some disagreement on what consonants he was saying. "His consonants are kind of blurry in the same way that mine might be if I'd had a half a bottle of Jack Daniel's or something," says Fitch.
What most struck the researchers is that Koshik was apparently so driven to imitate sounds that he invented the method of putting his trunk in his mouth and moving it around. They believe that he may have done this to bond with his trainers, as he was deprived of elephant companionship during a critical period of his childhood and spent years with humans as his only social contact.
Researchers now want to know exactly what he is doing with his trunk that produces the effect. And Stoeger says this raises the question of whether elephants in the wild also use vocal imitation for some kind of social bonding. "And now we can actually go and check whether elephants in their natural communication system will use this ability in a similar way but not as obviously," she says.
Stoeger also says studying the rare examples of vocal learning in the world of mammals could help shed light on why this ability evolved in humans. "There are such different species that share this ability, and why would that have developed?" she asks, noting that the question is important because this vocal imitation is so essential for things like language and music.