For thousands of years, humans have used names to communicate with one another. We also give names to animals, especially ones we love, such as pets. Until now there has been little evidence of animals naming one another, but a new study suggests that elephants use specific noises to identify other elephants.
A few animals, including parrots and dolphins, have been known to use sounds that are similar to names. Each dolphin invents a signature whistle that is unique to it, and other members of its species communicate with it by simulating this special call. The new study, led by Michael Pardo of Colorado State University, shows that wild African elephants use names in a way that is not just copying sounds and is much closer to the way humans use names.
For the study, the researchers recorded 625 sounds made by wild African elephants in Kenya that they called "rumbles (隆隆声)". This is the most common type of call produced by elephants, and it can travel long distances-as far as 3. 7 miles. It takes place at a very low frequency, which means humans can't hear it.
The researchers analyzed the sounds using computers and found that certain rumbles were directed at specific elephants to get their attention They found that all the elephants in the herd used the identical call to get a particular elephant's attention -these calls were not just nicknames used by one of the elephant's friends. Also. unlike the way dolphins communicate. the rumbles were not just imitations of the elephant they were trying to communicate with.
The researchers then played back some of the recorded rumbles to the elephants. They found that elephants responded more to their own name than to other calls. coming toward it more quickly or calling back faster. Cartlin O'Connell-Rodwell, an elephant expert, said, "The study shows that elephants can still keep in touch with one another even across a large area. "She told Live Science, "The rumbles ere magical, which allow them to spread out much further and still have very close tabs（密切关注） on individuals. "
