The behaviour of a naked mole-rat is determined by its role within the group. Photo: ImageSelect.
From cleaner to transporter: naked mole-rats fulfil six distinct roles, comparable to the division of labour in insect colonies.
Naked mole-rats (Heterocephalus glaber) turn out to have a strict division of labour: their colonies consist of six fixed types of worker, with roles reminiscent of those in insect societies. This is reported by Japanese biologists on 8 October in Science Advances.
Tunnel systems
The researchers tracked 102 animals from five colonies over thirty days in artificial tunnel systems in the laboratory, using an automated tracking system that recorded more than 83 million movements via subcutaneous microchips. The results show that these subterranean rodents do not all do the same thing. Some animals continuously drag material between chambers and act as transporters; others clean the toilet areas or remain in the nest chamber, where they tend the nesting material and interact with other mole-rats. A quieter group, consisting mainly of young and older animals, generally stays inside and appears to serve as a reserve.
Division of labour
The queen and her males often rest together and move through the tunnels in a coordinated fashion, forming the social core of the group. In contrast to the six worker types, the reproductive animals all display the same behavioural pattern. The six worker roles remain stable for weeks and are associated with age and body weight – indications of a lasting division of labour within the colony.
A day later, Science published another study on the naked mole-rat: four amino acid changes in the enzyme cGAS make their DNA repair exceptionally efficient, which may partly explain their lifespan of nearly forty years.