Dominant” ants favored over “Discoverer” ants inside human settlements

Increased biodiversity loss caused by humans underlines the importance of monitoring the health of ecosystems. One efficient way to do this is through the use of indicator species. Ants show potential as an indicator taxon, but the effect of human disturbance on their communities has not yet been well studied. In natural communities, ant species specialize to varying degrees in either discovery of food resources or aggressive domination of them, but this pattern has not been investigated in the context of human development. In order to find out whether human settlements lead to changes in ant community composition and discovery/dominance dynamics, we set 38 baited traps in matched pairs inside and outside of human settlements. We identified the responding ant genera, recorded activity levels every 10 minutes for one hour, recorded time of discovery and aggressive dominance interactions. “Discoverer” genera occurred at higher frequencies at sites outside human settlements, and “Dominant” genera occurred at higher frequencies at sites inside human settlements. Across all genera, ants arrived to bait traps faster outside of settlements than in them. High beta diversity was observed between inside and outside experimental sites, therefore human settlement at the level of the Leokwe Camp in Mapungubwe National Park appears to change the composition of ant communities. In resource-rich human areas there seems to be less pressure to discover food resources quickly, but increased pressure to defend resources from competitors.