Ant behaviour in the Anthropocene: A meta-analysis of human-induced environmental change effects on ant behaviour

Determining how recent and ongoing global changes will impact species is a key challenge facing modern biology. In particular, an important issue is investigating the extent to which species are able to cope with human-induced rapid environmental change (HIREC). Physiological and morphological changes caused by HIREC have been extensively evaluated in recent years, but the impact on behaviour has received less attention. This is quite surprising, given that changes in behaviour are often the first adaptive response to environmental disturbances, and can therefore be quickly detected. In (eu)social species, like ants, this behavioural plasticity can occur both at the individual and colonial level. Furthermore, due to their remarkable geographical distribution and therefore different exposures to human changes, ants are an ideal model to quantify the effects of HIREC on behaviour. We thus performed a systematic literature review on the effect of HIREC on ant behaviour. We used strict guidelines and an artificial intelligence-aided meta-analysis protocol. Of the 1394 studies assessed from the original WoS search, 52 were included in the qualitative and 45 in the quantitative analysis. We highlighted a bias towards studies assessing temperature increase and focusing on foraging behaviour. Considering the different behaviours observed, we found no general pattern, but positive and negative effects associated with specific types of disturbance (e.g. a negative effect of habitat degradation and drought on mutualistic interactions). We discuss the significance of our results, emphasising the necessity to extend and diversify studies on ant behaviour in response to global changes.