Dominance and policing in bumble bees

A fundamental problem in behavioural ecology concerns the stability of social systems. Social systems are threatened by within-group cheats that selfishly use group resources for personal reproduction. When cheating becomes too frequent, the result is group collapse through resource depletion (a tragedy of the commons). In animal societies, key processes keeping cheating in check, and so maintaining group stability, include dominance (one or a few powerful individuals suppress cheats) and policing (individuals mutually inhibit cheating behaviour). This project aims to address major, unanswered questions about these processes using the bumble bee Bombus terrestris. In this species, workers lay male-producing eggs in queenless colonies, but the group risks collapse if there are too many egg-layers. Egg-laying workers show dominance behaviour, but a link between dominance and reproductive success, though frequently assumed in this and comparable systems, has rarely been demonstrated. In addition, a leading theory for how policing originates, via reproductive competition between dominants (selfish policing), remains to be tested. The specific objectives of the project will therefore be to test the hypotheses that (1) queenless workers form dominance orders in which rank correlates with reproductive success and (2) policing (by egg-eating) in colonies with a queen originates as reproductive competition between dominant, egg-laying individuals, i.e. as selfish policing.

The student will obtain B. terrestris colonies from commercial suppliers and maintain them in the laboratory. He/she will then test the hypotheses using observations, digital filming and experimental manipulations of marked individuals. He/she will also conduct parentage analyses based on existing microsatellite markers, supplemented by a new panel of SNPs (single nucleotide polymorphisms) developed by the student. Use of SNPs will enhance the resolution of the microsatellite-based analyses. The student will receive full research training and generic, transferable training within the project, and cohort training provided by the EnvEast DTP. Research training will be in behavioural ecology, social insect biology, experimental design, molecular genetics and data analysis. Generic, transferable training will include project management, effective written and oral communication and career development. The student will be a member of a well-supported research group specialising on social biology of bumble bees, with access to all required facilities. All group members are encouraged and supported in conference attendance and public engagement. The student will also be free to shape the direction of the project for themselves as it develops.