The naked mole rat, which lives in burrows in the ground because it has little hair, is a mystery animal attracting attention in the medical community. This is because the average life span is more than 10 times longer than that of rats, and unlike other mammals, they do not suffer from cancer. In addition, the naked mole rat is a very special animal that does not follow the ‘Gompetz mortality rule’, which says that the mortality rate increases with age.
However, another characteristic of the naked mole rat was discovered. This is the result of a study that shows that these people use their own dialect for each group like humans. Moreover, it turns out that the reason they use the dialect is surprisingly to strengthen the sense of belonging and solidarity of the group.
A study has shown that naked mole rats, like humans, speak their own dialect for each group. ©Felix Petermann (MDC)
The naked mole rat is a mammal, but like an ant or a bee, it is a true social animal. Like a queen ant or a queen bee, one female and a small number of males as queens take over the breeding of the whole group, but the rest of the members who are unable to reproduce become the warrior class or the worker class, and only protect the nest or retrieve food.
Therefore, this animal is very active in communication. Listening to their burrows makes it easy to hear quiet chirps or loud squats. Dr. Gary Lewin of the Max Delbrueck Institute for Molecular Medicine (MDC), who has been studying naked mole rats for about 20 years, set out to find out how such sounds function in these socially organized animals with a strict division of labor.
Doesn’t respond to the dialect of other groups
First, the researchers recorded a total of 36,190 sounds produced by 166 animals in 7 groups to analyze their language, and then analyzed the acoustic characteristics of individual utterances using an algorithm that could compare eight different factors.
As a result, the researchers found that each naked mole rat has its own voice and can identify individuals based on that voice. In addition, as a result of research using artificial intelligence, we found similarities in the sound types of a single group.
In other words, this animal can identify which group a specific entity is by listening to the sound. This means that each group has its own unique dialect.
So, can these animals really distinguish the dialect between their own group and other groups? To find out, the researchers devised a special device. One naked mole rat was placed in two rooms connected through a tube, and then the cry of another entity was heard only in one room.
In order to analyze the language of the naked mole rat, the researchers recorded a total of 36,190 sounds made by 166 animals in seven groups, and then analyzed the acoustic characteristics of individual vocalizations. ©Felix Petermann (MDC)
Then the animal immediately moved to the room where the sound was heard. However, when the sound of other groups was heard, there was no reaction without moving.
The researchers created an artificial sound that contains the characteristics of a specific group dialect, but does not resemble the voice of a specific individual, to determine whether the behavior responds to the dialect or the voice of a specific individual. As a result, these animals were found to respond to the dialect of a specific group rather than the voice of a specific individual.
Queen controls and preserves dialect
The result was the same in the experiment in which a room where one group’s dialect was heard and another group’s smell was added. This means that naked mole rats are more responsive to dialect than the group’s smell. It was also revealed that the orphaned young naked mole rats were put into different groups, and that the pups acquired a new group of dialects.
However, in the course of further experiments, the researchers discovered another new fact. It was found that when the queen in charge of the group’s reproduction disappears, the vocalizations of the group individuals change differently than usual over time.
This means that the Queen Bare Mole Rat plays a crucial role in controlling and preserving the dialect of a group. The research results, jointly conducted by MDC’s Dr. Gary Lewin’s team and researchers at the University of Pretoria, South Africa, were published on January 29, in the international journal Science.
“The next task is to find out which mechanisms in the brains of these animals developed language culture faster than humans,” said Dr. Gary Lewin, who led the study. “It gives us an important insight into how human culture has evolved. It is because I can give it.’
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