Wild elephants have demonstrated a rare ability among animals: communicating with others in their social circle using their respective "names." New research suggests their human-like communication methods may mean elephants are capable of complex thinking.
As a species, humans are quite unique in that we call each other by names. This process of using sound tags to identify another person is learned; people are not born knowing the names of all their family members and social contacts. Dolphins and parrots use signature calls to "broadcast" their identities to other species, which are then imitated, but humans do not imitate.
Now, a new study from researchers at Colorado State University's Warner School of Natural Resources, conservation groups Save the Elephants, and Voice of the Elephants confirms that wild elephants in Africa communicate in a similar way to humans, calling each other using specific, "name-like" individual calls.
"Dolphins and parrots address each other by their 'name' by imitating the characteristic calls of the person being addressed," said Michael Pardo, lead author and corresponding author of the study. "In contrast, our data suggest that elephants do not rely on imitating the recipient's call to address each other, which is more similar to how humans address each other."
Human language is very arbitrary because the words we use are just labels. It is impossible to deduce the inner meaning of a word from its form. For example, "table" doesn't mean it's a table; it's just a conventional term. Because it is not imitation, arbitrary communication is considered more cognitively demanding.
"If all we can do is make sounds that sound like what we're talking about, then our ability to communicate is going to be extremely limited," said George Wittemire, a professor at UC's Warner School of Natural Resources, chair of Save the Elephants' scientific committee and senior author of the study.
Names are also arbitrary when it comes to self-identification. Researchers say elephants' use of arbitrary sound tags suggests they may be capable of creative, abstract thinking.
University of California study finds elephants have names just like people
Elephants and humans are both highly communicative animals and live in complex social networks. Like humans, elephants function within family units, social groups and larger clan structures. As with humans, this complexity likely drives elephants' need to name other elephants, the researchers say.
"This may be a situation where we face similar stresses, primarily from complex social interactions. That's one of the exciting things about this study; it gives us some insight into the possible drivers of why we evolved these abilities," Wittemire said.
Elephants make a variety of sounds, ranging in frequency from familiar trumpets to deep rumbles. Some of them are inaudible to humans. Kurt Fristrup, a research scientist at UC Walter Scott School of Engineering, developed a signal processing technique to detect the nuances of calls, and then he and Pardo trained a machine learning model to correctly identify which elephant was calling based on the call's acoustic characteristics alone.
"What's most fascinating is that we found that elephants do not simply imitate the sounds associated with the individual they are calling," Fristrup said. "Elephants are able to use arbitrary sound tags to represent other individuals, which suggests that there may be other types of tags or descriptors in elephant calls."
Scientists call elephants by name, and elephants respond
When elephants hear recorded phone calls from family and friends, they enthusiastically call back or move closer to the speaker. When the calls were made to other members of the herd, the animals responded less enthusiastically, suggesting they recognized their names.
"They may have been momentarily confused by the sound being played back, but ultimately just dismissed it as a strange event and went on with their lives," Pardo said.
The researchers found that elephants called each other's names more often when they were at a distance or when adults were talking to their calves.
The researchers also need more data to isolate individual names in the calls, or to determine whether the elephants say other names such as food, water and places. So it will be many years before we can talk to these majestic-looking animals.
"Unfortunately, we can't have them talk into the microphone," Witmeier said.
The research was published in the journal Nature Ecology & Evolution.