Environmental Drivers and Biogeographic Patterns of South American Endemic Ants: Insights From IUCN Red List Assessments

Abstract

Aim South American endemic ants play a central role in terrestrial ecosystems but remain poorly integrated into continent‐scale conservation assessments. Their distributions and community composition have likely been shaped by past climatic dynamics and persistent refugia. Here, we evaluate how historical climate stability and recent climatic change have influenced the distribution and turnover of endemic South American ants, testing the hypothesis that niche conservatism and differential species responses to temperature and precipitation drive patterns of historical persistence and compositional change. We further hypothesize that regions with low climate change velocity acted as refugia sustaining higher compositional stability from the LGM to the present. Methods Using IUCN‐validated occurrence data and ensemble species distribution models projected for the LGM and current climates, we derived binary suitability maps, calculated climate change velocity and quantified species co‐occurrence and turnover (TITAN2 and Jaccard turnover). Model ensembles demonstrated high predictive power (mean AUC = 0.905; Sørensen = 0.901) and enabled robust mapping of gains, losses and stable refugia across species. Results It was identified an average required range shift of ~0.017 km·yr. −1 , with 43% niche loss, 32% persistence (refugia) and 25% predicted gains across species; climatic thresholds in minimum winter temperatures and precipitation variables were key drivers of species responses. Main Conclusions These findings highlight climatically stable regions as conservation priorities for endemic ants and emphasize the urgency of preserving historical refugia under ongoing climate change.

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