Behavioural plasticity in a solitary foraging ant: Effect of experience and food distribution

To deal with the unpredictability of available food resources, animals must adjust their behaviour to optimise foraging efficiency. Various mechanisms influence food acquisition behaviour, and our knowledge of their combined impact on foraging efficiency often remains limited. In this study, we conducted laboratory experiments with seven colonies of the solitary foraging ant Dinoponera quadriceps. We observed the behaviour of foragers in an experimental set-up where ten food items were provided either in aggregated or dispersed distributions. Individual participation was voluntary (i.e., ants were free to enter or not the experimental arena), allowing us to assess internal processes like motivation for foraging. We recorded, across repeated trials, foraging activity and exploratory behaviour as proxies for foraging motivation, and success as a measure of efficiency. We found that foragers were highly efficient (retrieving food in 77.38 % of the trips), especially when exploiting aggregated and abundant food resources. Individual foraging success increased with higher exploration, which was more intense in environments displaying larger numbers of dispersed prey items. Individual activity was higher with more experience and in smaller colonies with fewer foragers. On the other hand, success declined when more conspecific foragers were present. 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 behaviours such as foraging. Additionally, they emphasise the importance of individual traits for effective task performance within social groups, an understudied topic.