Elephants Produce Alarm Call in Response to Threat from Humans

A study of wild elephants in Kenya revealed that the African elephants react quickly to the danger of humans by producing a specific alarm call.

Oxford University, Save the Elephants and Disney's Animal Kingdom  conducted a battery of audio experiments on the wild elephants of Kenya and discovered that in the presence of humans, the elephants became more vigilant and ran away with a distinctive low rumble.

The study also discovered that the alarm calls produced by the African elephants can be differentiated into two types of responses to threats and also reflects the level of urgency of a particular threat or danger.

During the audio experiments, the researchers collected the audio recording of a local North Kenya tribe 'Samburu'. The recorded audios were played to the resting wild elephants. The researchers noted that the elephants moved away from the sounds emitting a low rumble.

The team recorded the rumble and played it again to a group of wild elephants and saw a similar reaction. The elephants reacted in the same manner as they reacted to the sounds of the Samburu tribe. They were seen running away and becoming more vigilant looking for threats from human poachers.

This new finding is similar to the previous study of Oxford University that showed elephants identify and run away from the sounds of angry killer bees.

Though the rumbling alarm calls to human threat or bee threat may sound similar to the human ear, there are certain significant differences, which are audible at low frequencies that only the elephants can catch immediately.

"Elephants appear to be able to manipulate their vocal tract (mouth, tongue, trunk and so on) to shape the sounds of their rumbles to make different alarm calls," said Dr Lucy King of Save the Elephants and Oxford University, who led the study. "We concede the possibility that these alarm calls are simply a by-product of elephants running away, that is, just an emotional response to the threat that other elephants pick up on."

They also noticed that their alarm calls produced in response to human threat did not include any head shaking behavior, which was evident when threatened by angry bees. The elephants shake their heads in order to get rid of the insects. The adult elephants are more prone to be stung in their eyes or trunks by the bees and the baby elephants are at risk of being killed.

The difference in the bee alarm rumble and the human alarm rumble was similar to the vowel change used in human language. Dr King explains, "Interestingly, the acoustic analysis done by Joseph Soltis at his Disney laboratory showed that the difference between the ''bee alarm rumble'' and the ''human alarm rumble'' is the same as a vowel-change in human language, which can change the meaning of words (think of ''boo'' and ''bee''). "

This study is being used to lower the ongoing human-elephant conflict in Kenya.

"In this way, local farmers can protect their families and livelihoods without direct conflict with elephants, and they can harvest the honey too for extra income, "says Dr King. "Learning more about how elephants react to threats such as bees and humans will help us design strategies to reduce human-elephant conflict and protect people and elephants."

The finding was reported in the journal PLOS One.