Washington – The elephants Africans call each other and respond to individual names, something few species of wild animals do, according to a new investigation published on Monday.
The names are a part of the low murmurs that elephants can hear for long distances across the savanna. Scientists believe that animals with complex social structures and family groups that break up and reunite may be more likely to use individual names.
“If you're taking care of a big family, you have to be able to say, 'Hey, Virginia, come here!'”said Duke University ecologist Stuart Pimm, who was not involved in the study.
It is extremely rare for wild animals to call each other by unique names. We humans have names, of course, and our dogs come when their name is called. Baby dolphins make up their own names, called distinctive whistles, and parrots can use names too.
Each of these species also possesses the ability to learn to pronounce unique new sounds throughout their lives, a rare talent that elephants also possess.
For the study in Nature Ecology & Evolution, biologists used machine learning to detect name usage in a sound library of savanna elephant vocalizations recorded in Samburu National Reserve and Amboseli National Park in Kenya.
The researchers followed the elephants in jeeps to observe who called and who seemed to respond: for example, if a mother called a calf, or a matriarch called a straggler who then rejoined the family group.
Analyzing only the audio data, the computational model predicted which elephant it was addressing 28% of the time, likely due to the inclusion of its name. When fed random data, the model only correctly labeled 8% of the calls.
“Like humans, elephants use names, but they probably don't use names in most expressions, so we wouldn't expect 100%.”said study author and Cornell University biologist Mickey Pardo.
Elephant murmurs include sounds that are below the range of human hearing. Scientists still don't know which part of the vocalization is the name.
The researchers tested their results by playing recordings to individual elephants, who responded more vigorously, with ears moving and trunks raised, to recordings containing their names. Sometimes elephants completely ignored vocalizations directed at others.
“Elephants are incredibly social, always talking and touching each other. This naming is probably one of the things that underpins their ability to communicate with individuals,” said co-author and Colorado State University ecologist George Wittemyer, who is also a scientific advisor for the nonprofit Save the Elephants.
“We have just opened the door a little to the elephant's mind.”