Group level trait and individual performance: the impact of in-nest activity on food recruitment in ants

Abstract

By being consistent and colony specific, the activity level inside insect societies may be considered as a group level personality trait. However, there is no information about how this group level trait relates to the behaviour of individual workers and how it may affect colony efficiency. In this study, we correlated the levels of in-nest activity in eight ant colonies with the levels of individuals’ commitment to food recruitment and with collective foraging outcomes. Results showed that this group level trait is differentially related to the activity of individuals depending on whether they are recruiting foragers or workers contacted in the nest. For the foragers that had discovered a sugar food source, a high in-nest activity did not affect their recruiting behaviour. Conversely, for contacted individuals, their responsiveness to recruitment stimuli correlated positively with colony in-nest activity. However, this effect was too small to accelerate colony foraging dynamics and increase the number of workers at the food source. This study suggests that a group level trait, such as the in-nest activity, can be correlated with the individual behaviour of its members, albeit to a different extent depending on their role within the society. Similarly, in other group-living species, we expect complex and nuanced relationships between group level traits, individual responses and emergent collective behaviours. Future comparative studies will shed light on factors such as mode of communication that may weaken or strengthen links between personality traits at different organizational levels.