Behavioral flexibility in solitary foraging ants: how experience, colony size and food distribution shape individual and collective performance

To deal with the unpredictability of available food resources, animals must adjust their behavior to optimize foraging efficiency. Various mechanisms can influence an individual’s food acquisition behaviour, and thus our knowledge of their combined impact on foraging efficiency remains limited. In this study, we conducted laboratory experiments with seven colonies of the solitary foraging ant Dinoponera quadriceps. Foragers were individually observed in semi-controlled experiments where food was offered in aggregated or dispersed distributions. During the experiments, individual participation was voluntary (i.e. ants were free to enter or not the experimental arena), giving us an opportunity to assess internal processes such as motivation. Besides, behavioral traits such as foraging activity, exploration of food patches, and performance were recorded across repeated trials. We found that solitary foragers of D. quadriceps were highly efficient (retrieving food in 77.38% of the trips), especially when exploiting aggregated and abundant food resources. However, individual foraging success declined when more conspecific foragers were present and with longer foraging experience. Foragers increased their exploration levels in environments with larger numbers of dispersed prey items. Individual foraging activity was higher with more experience and in smaller colonies with fewer foragers. Furthermore, foragers and colonies exhibited low but consistent differences in levels of activity, exploration, and success rates. These findings provide a comprehensive view of how different factors combine to give rise to complex behaviors such as foraging. Additionally, they emphasize the importance of individual traits for effective task performance within social groups, an understudied topic.