Mapping Risk Zones: niche overlap between Batrachochytrium dendrobatidis and endemic amphibians in Mexico’s Central-Southern Highlands

Amphibians are amongst the most threatened vertebrate groups worldwide and population declines are driven by climate change, habitat degradation and the spread of emerging infectious diseases. One of the most devastating pathogens is Batrachochytrium dendrobatidis (Bd), the causative agent of chytridiomycosis. In Mexico – a global hotspot of amphibian diversity and endemism – Bd has been reported in numerous taxa. However, studies addressing the potential distribution and ecological niche overlap of this species with native amphibians are limited. In this study, we modelled the potential distribution of Bd alongside 13 amphibian species from three families: Hylidae , Ambystomatidae and Plethodontidae . Species were selected, based on their conservation status, endemicity and data availability, particularly for Pseudoeurycea , which remains poorly studied beyond presence records. Ecological niche models (ENMs) and niche overlap analyses revealed extensive spatial congruence between Bd and amphibian distributions, especially within the Trans-Mexican Volcanic Belt and Sierra Madre del Sur — regions already recognised as amphibian biodiversity hotspots. Our findings highlight the high environmental suitability of these plants for both Bd and amphibians and reveal critical areas where the risk of disease transmission may increase. These findings emphasise the urgency of implementing targeted conservation actions, including long-term monitoring, early detection of infections, identification of resistant or tolerant populations and regulation of ecotourism in vulnerable regions. Mapping zones of overlap provide valuable guidance for prioritising areas for disease mitigation and habitat protection, particularly for endangered and endemic amphibian species. Our study offers novel insights into the spatial dynamics of Bd in Mexico and contributes to the development of proactive strategies for amphibian conservation.