DENVER - Elephants can tell how dangerous people are simply by the sound of our voices.
Grame Shannon, a researcher at Colorado State University, studied Wild African elephants in Kenya for two years. Using a camouflaged loud speaker, he and his research partner played different human voices to nearly 50 different elephant groups. Some of the voices belonged to the Maasai, an ethnic group of semi-nomadic people in Kenya. They sometimes spear elephants over access to water or grazing areas. Because the elephants see the Maasai as a threat, when the animals heard their voices, they immediately bunched together and started to retreat.
When researchers played the voices of a different ethnic group - the Kamba - the reaction was very different. Because the Kamba are less of a threat, the elephants reacted, but not as intensely as they did with the Maasai
"We expected it to be quite difficult for them to judge between languages, but they were pretty good at that. They excelled at telling the difference between male Maasai and male Kamba. Then, we found out that they can even distinguish between female Maasai and male Maasai," said Shannon. "The reason elephants are such an interesting species to study is because they are large brained, long-lived so they are very intelligent. They can acquire social and ecological information in these long lifetimes, which we can explore using these playback experiments."
Shannon's research has gotten international attention. It was even featured in National Geographic.
"I think it has struck a cord with people and the ability of elephants to distinguish us because it brings in this kind of human component with the elephants. So, elephants are kind of using our language and our acoustic cues when we speak to make distinctions of what threat level we present. Not just humans in general, but individual groups of humans. That's incredibly complex," said Shannon.
Elephants aren't native to Colorado, so you might be wondering what Shannon is doing at CSU. He is now studying prairie dogs and how they react to different sounds.