Conflict of interest and dominance hierarchies: Individual and social responses to health threats in queenless societies.

• Applicant: Dr. Priscila Hanisch
• Subject Area: Sensory and Behavioural Biology ; Animal Physiology and Biochemistry ; Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 572810970

Insect societies exhibit a division of labor between reproductive and non-reproductive members. In many species, reproductive functions are monopolized by morphologically specialized individuals, while non-reproductive members engage in other tasks, such as foraging for food. However, in some species, morphologically similar individuals retain equal reproductive potential. This is the case of the giant ant Dinoponera grandis, a queenless species where workers can mate and lay fertile eggs. Reproduction within the colony is regulated through a complex interplay of chemical signaling and behaviour, establishing a dynamic dominance hierarchy where only the most dominant female reproduces. However, the aggressive interactions required to maintain this hierarchy can be costly to both individuals and the colony, often resulting in injuries or destabilizing the colony’s social structure. Notably, injured individuals may receive care from nestmates, who lick wounds and apply metapleural gland secretions, potentially reducing infection risks and mortality within the colony. This project will use D. grandis as a model species to investigate social conflict, wound care behaviour, and social immunity in animal societies. By experimentally exposing individuals of different hierarchical ranks to pathogenic agents or injury, I will quantify both individual and colony responses, including any shifts in the social status of the affected individuals. This study will be the first to examine wound care behaviors (WP1) and social immunity responses (WP2) within a society that has both dominance hierarchies and a reproductive worker caste. Additionally, I will analyze how individuals signal or conceal their injured or infected status through cuticular hydrocarbon compounds (WP3). Overall, this project aims to uncover the mechanisms by which a queenless society regulates conflicts of interest among individuals and adapts to health threats. The outcomes of this research will provide valuable insights into social evolution, social conflict, cooperation, and social immunity — topics increasingly relevant for understanding how social groups manage internal conflicts and respond to health challenges.

• DFG Programme: Research Grants