Global climate-driven shifts in the distribution of Rhipicephalus annulatus, a major vector of bovine babesiosis

Abstract Climate change is reshaping arthropod biodiversity by altering species’ ecological niches and driving range shifts with important implications for ecosystem resilience and livestock health. Rhipicephalus ( Boophilus ) annulatus , a key tick vector of bovine babesiosis, represents a growing threat to livestock populations and associated ecosystems under warming climates. We applied ecological niche modelling (ENM) to assess the current and future climatic suitability of this species using occurrence records from the Global Biodiversity Information Facility (GBIF), VectorMap, and published literature, combined with bioclimatic variables from WorldClim within different climatic scenarios and time periods. Models were calibrated using a systematic framework incorporating spatial filtering, tuning of feature classes and regularization multipliers, and model selection based on statistical significance, omission rates (< 5%), and ΔAICc to optimize predictive performance and minimize overfitting, and subsequently projected under SSP2–4.5 and SSP5–8.5 climate scenarios for mid- (2041–2060) and late-century (2081–2100) periods. Current climatic suitability is concentrated across Africa, the Middle East, and South Asia. Future projections indicate substantial climate-driven expansion of the species’ ecological niche, particularly under SSP5–8.5, with emerging suitability across parts of Europe, the Arabian Peninsula, and Australia. Threshold-based binary projections and gain–loss analyses further reveal a net increase in suitable areas under mid-century scenarios, followed by partial contraction under late-century high-emission conditions, indicating a nonlinear response to climatic change. These findings highlight the sensitivity of ixodid ticks to climatic variability and suggest a progressive broadening of suitable habitats into previously unsuitable regions. Overall, the results underscore the importance of integrating climate-informed surveillance within One Health frameworks, where early warning systems and adaptive strategies will be critical for managing emerging vector-borne risks under ongoing global environmental change.