I am mainly interested in the social organisation of highly polygynous ant species. We use the ant Formica exsecta as a model species to investigate sex investment and reproductive skew.
Sex investment: Brown and Keller (2000) showed that sex allocation within a colony varies not like in many other ants with relatedness asymmetry but with queen number. This led the authors to propose a new hypothesis: The queen replenishment hypothesis. One aim of my PhD is to find more evidence for this hypothesis by the following two approaches. First, we conducted an experiment in the field by removing and adding queens from colonies to test whether colony sex ratio changes according to the predictions of the queen replenishment hypothesis. Second, I carry out a long-term study on focal colonies to test whether the cyclical pattern of sex ratio occures how it is predicted by the queen replenishment hypothesis.
Reproductive skew: I am working on studies in the field and in the laboratory to find out how nest-mate queens share their reproductive output and whether queens are specialised in the production of a specific caste.