Behavioural interference among eusocial naked mole rats during work
It has been reported that individuals of cooperative breeding species occasionally interfere with the work of other group members. However, the occurrence and function of this behaviour are controversial. In the naked mole rat (Heterocephalus glaber), a eusocial mammal, individuals frequently perform ‘tail-tugging’ behaviour, in which an actor holds the tail of another individual with the mouth and pulls that individual to a different place. In this study, we investigated the possible function of this behaviour in the experimental setting of soil excavation. Behavioural observations on three colonies showed that this behaviour was performed and received by individuals of all individual categories (i.e. queen, reproductive males, and workers), although a queen in one colony performed 72.5% of the observed behaviour. Our data support the hypothesis that this behaviour is used to monopolise work in a specific space because (1) tail-tugging was more likely to occur when the actor and recipient were working than when they were not, and (2) the actor performed tail-tugging in a cell in which that individual worked frequently. This study provides a rare example of behavioural interference in a cooperative society and suggests that there is disagreement and conflict regards the opportunity to work among colony members in this eusocial mammal.
KeywordsEusociality Cooperation Heterocephalus glaber Tail-tugging Conflict
We thank S. Yoshida and S. Nambu for their support over the course of this study. We also thank K. Miura for providing a video clip of mole rat tail-tugging behaviour. This study was supported financially by the Japan Society for the Promotion of Science, the Special Postdoctoral Researcher program at RIKEN, the ESB Cooperation Program, SOKENDAI (the Graduate University for Advanced Studies), and Japan Science and Technology Agency, Ministry of Education, Culture, Sports, Science and Technology (MEXT; grant numbers 18870025, 2077023).
Supplementary material 2 (MOV 80439 kb) ESM 2: Video of tail-tugging behaviour
- Bennett NC, Faulkes CG (2000) African mole-rats: ecology and eusociality. Cambridge University Press, Cambridge, p 273Google Scholar
- Brett RA (1991) The ecology of naked mole-rat colonies: burrowing, food, and limiting factors. In: Sherman PW, Jarvis JUM, Alexander RD (eds) The biology of the naked mole-rat. Princeton University Press, Princeton, pp 137–184Google Scholar
- Lacey EA, Sherman PW (1991) Social organization of naked-mole rat colonies: evidence for the division of labor. In: Sherman PW, Jarvis JUM, Alexander RD (eds) The biology of the naked mole-rat. Princeton University Press, Princeton, pp 275–336Google Scholar
- Lacey EA, Alexander RD, Braude SH, Sherman PW, Jarvis JUM (1991) An ethogram for the naked mole-rat: nonvocal behaviors. In: Sherman PW, Jarvis JUM, Alexander RD (eds) The biology of the naked mole-rat. Princeton University Press, Princeton, pp 209–242Google Scholar
- Reeve HK, Sherman PW (1991) Intracolonial aggression and nepotism by the breeding female naked mole-rat. In: Sherman PW, Jarvis JUM, Alexander RD (eds) The biology of the naked mole-rat. Princeton University Press, Princeton, pp 337–357Google Scholar
- Sherman PW, Jarvis JUM, Alexander RD (1991) The biology of the naked mole-rat. Princeton University Press, Princeton, p 344Google Scholar
- Solomon NG, French JA (1997) Cooperative breeding in mammals. Cambridge University Press, CambridgeGoogle Scholar