Elephants can distinguish between human languages, determine our gender and relative age and move away from those considered a threat — all from the sound of our voice, a new study suggests.

African elephants (Loxodonta africana) can even differentiate between ethnicities and genders, and can tell an adult from a child, the study found.

“Animals associating sounds with danger is nothing new — but making these fine distinctions in human voices is quite remarkable,” said Frans de Waal, from Emory University.

Elephants in Kenya’s Amboseli National Park are killed periodically by Maasai pastoralists. Most of the time, the Maasai and elephants co-exist quite well, said Karen McComb, a behavioural ecologist at the University of Sussex in U.K.

It’s long been known that elephants flee when they encounter Maasai men wearing their distinctive red robes — yet they are far less bothered by other people on foot.

Ms. McComb and her colleagues set out to determine if the Amboseli elephants could make distinctions between the voices of the Maasai and Kamba people — farmers who live in the same area but don’t threaten the animals.

Scientists recorded men from the two ethnic groups, as well as Maasai women and boys, saying “Look, look over there, a group of elephants is coming” in their respective languages.

From a concealed loudspeaker, the team then played back the voice recordings to 47 elephant family groups.

“From the get-go, the elephants responded differently to the Maasai and Kamba male voices,” said study co-author Graeme Shannon, from the Colorado State University.

They were more likely to retreat and bunch together, forming a defensive fortress around their young, and to smell the air if they heard an adult Maasai man speak, Science Magazine reported.

However, their reaction was not as defensive when the voice was that of a male Kamba. The animals were also much less fearful on hearing the voices of Maasai women or boys.

Scientists also altered the recordings, making the adult male voices sound more female and vice versa. But the elephants weren’t fooled and remained vigilant.

Previously, researchers showed that elephants will often come aggressively toward the loudspeaker when they hear lions (their other predator) roaring, apparently to drive them off.

But when the elephants heard the adult Maasai male voices, they never showed this mobbing behaviour, and instead formed a defensive bunch and retreated stealthily.

And apparently because the Maasai men present such a serious threat, all the elephant matriarchs, including the youngest, knew how best to respond, researchers said.

“It’s a key skill and is learned by watching; it’s likely not hardwired,” Mr. Shannon said. “Older matriarchs appeared better at some voice discriminations — in particular, telling the difference between Maasai men and boys so that they only retreated when faced with men’s voices,” Ms. McComb added.

The study was published in the journal PNAS.

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