In fact, every elephant has its own name.

Produced by: Science Popularization China

Author: Wu Yu (Institute of Zoology, Chinese Academy of Sciences)

Producer: China Science Expo

Editor's note: In order to decode the latest mysteries of life science, the China Science Popularization Frontier Science Project has launched a series of articles called "New Knowledge of Life" to interpret life phenomena and reveal biological mysteries from a unique perspective. Let us delve into the world of life and explore infinite possibilities.

A group of African elephants are walking on the open grassland.

A herd of African elephants walking on the open savannah in Luangwa National Park, Zambia

(Photo source: veer photo gallery)

This is an extremely arid area. Elephants migrate in search of food, and their migration routes often pass through streams, lakes, swamps, etc.

In a walking herd, the leader is usually a female elephant, and most of the members are her female offspring; male elephants have no place in the herd and must leave the herd at the age of 15, returning only during mating. When the herd moves, they follow a certain order of status, whether eating, drinking, mating or walking, everything is in good order.

Behind this order are the unique sounds and smells used by each elephant group for communication. Elephants send different signals to other members by making different sounds to achieve friendly coexistence among the group.

Elephants gently touch each other (greeting)

(Photo source: veer photo gallery)

Human language is a sophisticated and complex system that has helped humans build societies and distinguished us as a species. A hallmark of the human language system is the use of "sound tags," that is, unique sounds that represent objects or individuals, and these sound tags are learned. Most human words, including names, are arbitrary: they are not imitations of the sounds made by the things they refer to, nor do they depend on their physical properties.

In the animal communication system, the sounds made by most species are responses to food, predators or other survival needs. Such calls are usually innate and rarely resemble human language labels. A few animals that can imitate novel sounds, such as the well-known parrots, can speak like humans, but this is only an imitation of human voices and does not have the "label nature" of the human social language system.

However, there are always "surprises" in nature. A recent study found that in addition to ordinary communication, elephants can also communicate more "precisely" like humans, that is, calling each other by name.

Next, let's follow the scientists' ideas to explore how elephants communicate accurately:

The scientists first obtained recordings of female offspring of wild African savannah elephants collected in the Samburu and Buffalo Springs National Reserves in Kenya from 1986 to 2022, and used a precise machine learning model to analyze the data. In the process of analyzing the data, the scientists raised four questions. Let's think about them together:

First, does this “name” belong uniquely to an elephant?

The scientific question is, are the calls made by elephants specific to a single recipient? The researchers classified the calls based on social relationships by relatedness and age group, and only considered calls with the same social relationship between the caller and the recipient. Calls with the same caller and recipient were significantly more similar than calls with the same caller and different recipients. This suggests that elephant calls contain information that is specific to a single recipient (left image below).

Left: Voices with the same caller and receiver have significantly higher similarity scores; Right: The similarity scores between the typical voice of the caller and the voice of the receiver in response are not significantly different from the similarity scores between the typical voice of the caller and other voices.

(Image source: Reference 1)

Second, does this “name” imitate the sound made by the elephant being called?

To put it in scientific terms, do these sound tags mimic the voices of the receivers?

If elephants call a single recipient by imitating the recipient's voice, then the vocal tag should sound more like the recipient's voice than when calling other individuals. The researchers compared the recipient's voice with the caller's voice when communicating with other elephants and found 59.7% inconsistency; the recipient's call was not very similar to the caller's typical voice, that is, the vocal tags were not imitating the recipient's voice (above right).

Third, do all elephants use this "name" to call the elephant being called?

The scientific question is, can different callers share the same sound label when calling the same receiver?

In humans and bottlenose dolphins, different callers often use the same vocal label for a given recipient. To determine whether elephants do this, the researchers further examined call proximity scores. Calls from different callers to the same recipient were significantly more similar than calls from different callers to different recipients (below, left).

Left: The sounds made by different callers to the same recipient were significantly more similar than the sounds made by different callers to different recipients; Right: The test group made more sounds when receiving playback than the control group

(Image source: Reference 1)

Fourth, does the elephant being called know that another elephant is calling it?

To put it in scientific terms, can the receiver identify the sound tag?

To determine whether elephants can sense and respond to vocal tags uttered by other elephants, the researchers compared the responses of 17 wild elephants to playbacks of vocalizations originally addressed to them (test group) with playbacks of vocalizations from the same caller originally addressed to different individuals (control group). These results further supported the existence of vocal tags, with subjects approaching the speaker faster and producing more vocalizations in response to the test group vocalizations rather than the control group vocalizations (above right).

In the study of linguistics, scientists use the models and methods of non-human primate research to reflect on the nature of human language. At the same time, from the perspective of neurobiology, it is proved that language is distributed continuously in a ladder-like manner among different species. Humans are advanced language learners, and some species are in the early stages of language learning. Perhaps language is not unique to humans.

The names shouted by elephants may contain the mysteries of the formation and evolution of language in human society.

References:

1. Pardo, MA, Fristrup, K., Lolchuragi, DS, Poole, JH, Granli, P., Moss, C., Douglas-Hamilton, I., & Wittemyer, G. (2024). African elephants address one another with individually specific name-like calls. Nature ecology & evolution, 10.1038/s41559-024-02420-w. Advance online publication.

2. Clemins, PJ, Johnson, MT, Leong, KM, & Savage, A. (2005). Automatic classification and speaker identification of African elephant (Loxodonta africana) vocalizations. The Journal of the Acoustical Society of America, 117(2), 956–963.

3. Soltis, J., Leong, K., & Savage, A. (2005). African elephant vocal communication II: Rumble variation reflects the individual identity and emotional state of callers. Animal Behavior, 70(3), 589–599.

4. Wittemyer, G., Douglas-Hamilton, I., & Getz, WM (2005). The socioecology of elephants: Analysis of the processes creating multitiered social structures. Animal Behavior, 69(6), 1357–1371.

5. Jarvis, Erich D.. “Evolution of vocal learning and spoken language.” Science 366 (2019): 50 - 54.