Critical Conservation Gaps for Microendemic Axolotls Reveal Inadequate Protection in Central Mexico

ABSTRACT: Salamanders of the genus Ambystoma in the Trans-Mexican Volcanic Belt are experiencing severe population declines due to habitat loss and fragmentation. This study evaluated critical protection gaps for four Critically Endangered microendemic species: A. amblycephalum, A. andersoni, A. dumerilii and A. mexicanum. We compiled and cleaned 89 validated presence records from databases and the literature. Refined areas of occupancy were calculated using minimum convex polygons adjusted with elevation masks, hydrographic network filters, and species-specific buffer zones (50–100 m). Bioclimatic variables (temperature and precipitation-based) were derived from MexHiResClimDB, and overlap with protected areas, and the Ecosystem Integrity Index (EII) was quantified. The resulting areas of occupancy (0.38–108.19 km²) were larger than previous IUCN estimates for A. amblycephalum and A. dumerilii, yet showed null or minimal overlap with protected areas for these two species (4.79% and 0%, respectively). Ecosystem integrity was low across all species (EII 0.05–0.43), indicating severe degradation. Climatic niches were narrow, differentiated, and associated with restricted altitudinal ranges. These results reveal a crisis of effective protection, where expanded distribution knowledge does not translate into improved conservation status, demanding urgent expansion of active conservation strategies to counteract severe habitat degradation caused by urbanization, intensive agriculture, pollution, and invasive species.