It is known that "eusocial" organisms such as ants and bees form highly specialized societies, characterized by a division of labor between breeding individuals (queens and breeding males) and non-breeding individuals that cooperate to maintain their social lives. However, many aspects of the naked mole-rat, a eusocial mammal, have remained poorly understood.
A research group led by Postdoctoral Researcher Masanori Yamakawa at the Faculty of Life Sciences, Kumamoto University; Professor Teruhiro Okuyama from the Institute for Quantitative Biosciences, the University of Tokyo; and Professor Kyoko Miura from the Faculty of Medical Sciences, Kyushu University have, for the first time, revealed the overall structure of naked mole-rat society and the social relationships between individuals. This was achieved through continuous behavioral analysis of entire colonies over a 30-day period. The research group developed a system to track individual movements using "RFID tags", which wirelessly identify each animal. Tags were implanted in 102 naked mole-rats across 5 colonies, allowing for the observation of their behavior. The results showed that breeding individuals play a monitoring role over the entire colony and are central to the society, while non-breeding individuals are divided into six behavioral types, including "workers," maintaining a stable division of labor. Furthermore, the study found that relationships with other individuals differ according to behavioral type, such as less mobile individuals avoiding activity in the same location as more active companions.
This research provides a foundation for future studies on sociality, offering insights into the mechanisms of cooperative societies and their maintenance across diverse animal species. The research group plans to further investigate how cooperative societies are maintained and how robust they are by intentionally introducing changes to colony social structure.
(Article: Masanori Nakajo)
