[LINK] "Elephants distinguish human voices by sex, age, ethnicity, study says"

[rfmcdonald]

The Los Angeles Times' Amina Khan (via Science NOW) reports on the latest evidence of the uncanny intelligence of elephants. Hunting them for ivory if they're that capable of distinguishing between human beings is seeming like murder now.

“The elephants can’t predict where the people are going to be because they range over these large areas, grazing their cattle,” said Graeme Shannon, a behavioral ecologist at Colorado State University who co-led the study. “So the threat is both spatially and temporally very variable -- and so they have to respond appropriately.”

Voices offer a rich range of auditory cues, and hearing someone from a distance can also give you a key advantage in the survival game if you know what to listen for. Previous research had already shown that elephants can tell the number and sex of lions based on their roaring, and the scientists wondered if the same were true for the elephants' other major predator, humans.

The researchers took a speaker, camouflaged it with a screen woven of palm fronds and placed it about 50 meters away from where they expected wandering elephants to end up. They pre-recorded calls from local villagers, including Maasai men, women, and young boys, saying, “Look, look over there: a group of elephants is coming.”

To compare to the Maasai, they also included calls from people known as the Kamba. Since the Kamba are farmers, not cattle herders, and their clearly defined cropland is easy for the elephants to avoid, they generally come into far less conflict with elephants.

[. . .]

Elephants did, however, react with alarm to the voices of Maasai men -- they quickly huddled, protecting the calves, and raised their trunks to sniff the air for any human scent. Recordings from Maasai women or boys didn’t earn anywhere close to that kind of reaction. Neither did the voices of Kamba men.

That’s because Maasai men are the ones most likely to hunt an elephant down, the scientists said. Women don’t get involved in hunting, the boys are too young, and the Kamba farmers generally don’t need to compete with elephants for resources.

The Kamba men spoke a different language than the Maasai, so it’s likely the elephants were picking up on linguistic cues rather than some underlying, inherited differences in their voices. But the scientists aren’t sure exactly how the elephants could tell the adult male Maasai voices from the women and boys’ voices. When they remixed the men’s voices to sound more like the women’s and vice versa, the animals weren’t fooled. Figuring out that mystery will be the job of future research, Shannon said.