There are some highly intelligent animals out there, like dolphins and chimpanzees. Scientists have now learned that elephants, some of the only animals that can recognize themselves in a mirror, call each other with vocalizations that are similar to names. This is an unusual ability in nonhuman animals, the scientists noted in the study reporting the findings, in Nature Ecology & Evolution.
In this work, the investigators made recordings of elephants in nature, and analyzed those recordings with computational tools. This allowed them to identify a component of the elephant sounds that indicated the intended recipient of a call, which was also based on field observations of the elephants.
When the recordings were played back for the elephants, the animals affirmatively responded by either approaching the speaker, or calling back when they heard they 'names,' while calls intended for other elephants garnered less interest.
"Dolphins and parrots call one another by 'name' by imitating the signature call of the addressee," noted lead study author Michael Pardo, who conducted the study as an NSF postdoctoral researcher at Colorado State University (CSU) and Save the Elephants, a Kenya-based research and conservation organization. "By contrast, our data suggest that elephants do not rely on imitation of the receiver's calls to address one another, which is more similar to the way in which human names work."
The sonic frequency of elephant vocalizations covers a huge range, from low rumbles to loud trumpeting, and they can also make noises that are below the audible range of what human ears can hear.
Elephants talk a lot, and can coordinate the movements of a group with calls over long distances. Their vocalizations also seem to contain a lot of information, such as details about the caller's age, sex, emotions, behaviors, and identity.
Animals have to be able to produce novel sounds to identify individuals by name, and seems to be quite an uncommon trait among animals. When a sound is representative of an idea it does not imitate; the sound has no obvious link to the meaning it conveys, it is considered to be arbitrary communication, which widely expands the applications of communication. It is also thought to be a next-level cognitive ability.
Elephants date back millions of years, and they live in highly social clans. Their complex social networks might have driven a need for more arbitrary vocal labeling. This may echo what happened in human societies.
"It's probably a case where we have similar pressures, largely from complex social interactions," suggested senior study author George Wittemyer, a professor at CSU. "That's one of the exciting things about this study, it gives us some insight into possible drivers of why we evolved these abilities."
Sources: Colorado State University, Nature Ecology & Evolution