When faced with danger, humans are likely to yell in alarm (for instance, "BEAR!!") while looking to get out of harm's way.
So, too, do elephants. And in research published late last month in Plos One, a team from Oxford University, Save the Elephants and Disney's Animal Kingdom reveal elephants may have developed a specific alarm for "Human!"
By playing audio recordings of the Samburu, a tribe in northern Kenya, to African elephants in Kenya, researchers found the elephants went on alert and ran from the sound, all while emitting a "distinctive low rumble" (click here for audio).
The team then recorded that "rumble," and played it to other elephants, who reacted similarly to the first group, as though humans were near.
"We concede the possibility that these alarm calls are simply a byproduct of elephants running away, that is, just an emotional response to the threat that other elephants pick up on," one of the researchers, Dr. Lucy King, told Oxford University's science blog. "On the other hand, we think it is also possible that the rumble alarms are akin to words in human language, and that elephants voluntarily and purposefully make those alarm calls to warn others about specific threats. Our research results here show that African elephant alarm calls can differentiate between two types of threat and reflect the level of urgency of that threat."
In 2010, researchers discovered elephants also have a distinctive "bee alarm rumble", which, when played, causes the animals to flee while shaking their heads, likely an attempt to kill the insects.
The unique responses to each different rumble has led scientists to postulate that elephants have more sophisticated verbal communication than previously realized.
"The acoustic analysis [of the rumbles] 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')," Dr. King explained to the Oxford blog. "Elephants use similar vowel-like changes in their rumbles to differentiate the type of threat they experience, and so give specific warnings to other elephants who can decipher the sounds."
African elephants are considered a "vulnerable" species as a result of poaching and a loss of habitat.