Aim: Foraging activity is critical for animal survival. Comprehending how ecological drivers influence foraging behaviour would benefit our understanding of the link between animals and ecological processes. Here, we evaluated the influence of ecological drivers on ant foraging activity and relative resource use.Location: Six Brazilian biomes: Amazon, Atlantic rainforest, Caatinga, Cerrado, Pampa and Pantanal.Taxon: Formicidae. Methods:We assessed ant foraging activity and resource use by sampling across 60 sites. We placed baited tubes that contained one of five liquid resources (sugar, lipids, amino acid, sodium and distilled water). We used model selection to assess the influence of ecological drivers (temperature, precipitation, temperature seasonality and net primary productivity) on ant foraging activity and relative resource use. Results:Foraging activity was higher in wetter, more productive and less thermally seasonal environments. The relative use of amino acids increased at higher temperatures while the relative use of lipids decreased. The relative use of sugar increased in drier and less productive environments with high-temperature seasonality while the relative use of amino acid and sodium decreased in those environments. The relative use of lipids was complex: increasing with increasing temperature seasonality and decreasing with increasing precipitation. Furthermore, the relative use of sodium was greater where the foraging activity was high. Main conclusions:We demonstrate how ecological drivers are correlated with ant foraging activity and resource use in the field across large spatial scales. The search for resources encompasses different interactions involving ants with abiotic and biotic components in the ecosystem. Thus, we suggest that changes in climate and NPP, which influence the intensity and the way that ants search for resources, will result in changes in ant-mediated ecological processes.

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Fluctuating resources and conditions can regulate the community structure of ants, affecting their activities and interactions. This has important implications for the selection of sampling periods during bioindication studies. The aim of this study was to evaluate if the chosen sampling period influences the response of ant assemblage diversity and ecological function to mining impacts and rehabilitation age after mining. We used ant assemblage parameters, including arboreal, epigaeic and hypogaeic ant species richness and composition, seed-removing ant species richness and composition, and seed removal rate in areas impacted by mining and with different rehabilitation ages. We showed that in most cases the response is the same, regardless of sampling period. However, we suggest that ant sampling is best undertaken in the rainy period, when ant species richness reaches higher values and the assemblage composition presents a well-marked difference among the areas. We also indicate that the epigaeic ant assemblage is sufficient for evaluating mining impacts, but arboreal strata should also be sampled in rehabilitation scenarios.

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