Artificial intelligence has discovered that different families of naked mole rats develop their own dialects that help them identify their own and others.
Sound communication is not uncommon among animals. However, only a few of them use their voice flexibly and create dialects specific to different groups and populations. Such features are known in cetaceans, bats, some birds and, of course, primates.
More recently, this “elite” list has been joined by naked mole rats - rodents already known for many unusual traits, including insensitivity to pain, resistance to cancer, surprisingly long lifespan, and eusociality. For rodents, this is a striking ability, in stark contrast to most mammalian vocalizations, which remain innate, unchanged, and genetically inherited.
Naked mole rats live in complex families, the number of which can reach a couple of hundred individuals, and constantly talk. They know at least 17 different voice signals, which serve as the most important means of interaction and forging relationships within the groups of these blind animals that never leave the dark underground holes. Therefore, their vocalizations are able to develop flexibly and form dialects.
The authors of the new article, published in the journal Science, collected and analyzed about 36 thousand signals recorded from 166 mole rats living in seven different colonies in laboratories in Germany and South Africa. Specially trained machine learning algorithms have found that members of different families can be identified by their voice.
This was also confirmed by experiments: when playing records, naked mole rats reacted to the signal of their relatives much more actively than to the voices of "outside" rodents. Moreover, the difference persisted in the reproduction of synthetic signals generated by pre-trained artificial intelligence. Animals only responded to those that were created based on their own dialect.
To find out if the peculiarities of vocalizations are innate, scientists planted newborn mole rats in other families. As a rule, they brutally expel strangers, but sometimes they can accept them into the group. It turned out that the animals, growing up in a new environment, learned the dialect of their new family.
Curiously, the flexible nature of the dialect makes it not very stable. The authors of the work found that in the period of "anarchy" - when the old "queen" of the family of naked mole rats dies, and the new one has not yet appeared - the peculiarities of the speech of the whole group begin to blur. However, with the accession of the next female, everything returns to normal - and a new dialect is fixed in the group.