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.

Keywords

Climatic niche / Ecosystem integrity / Geographic isolation / Habitat fragmentation / Paedomorphosis / Protected areas

Statement of the Use of Generative AI and AI-Assisted Technologies in the Writing Process

Claude AI (Claude Sonnet 4.6, Anthropic, San Francisco, CA, USA) was used to improve the writing style and clarity of the text; Kimi (Kimi K2.5, Moonshot AI, Beijing, China) was employed to eliminate redundancies and improve content cohesion; and Grok AI (Grok 4.1, xAI, Palo Alto, CA, USA) was used to verify English grammar and language accuracy. All AI-generated suggestions were carefully reviewed and validated by the authors, who take full responsibility for the manuscript content. These artificial intelligence tools were used solely for editorial assistance and did not contribute to the scientific content, data analysis, or intellectual conception of this work.

Author Contributions

Conceptualization, B.I.A.-A., H.A.C.-B. and D.R.A.-G.; Methodology, all authors; Software, B.I.A.-A. and H.A.C.-B.; Validation, H.A.C.-B. and J.A.V.; Formal analysis, B.I.A.-A. and H.A.C.-B.; Investigation, all authors; Resources, all authors; Data curation, H.A.C.-B.; Writing—original draft preparation, B.I.A.-A. and A.G.-Z.; Writing—review and editing, all authors; Visualization, B.I.A.-A., H.A.C.-B. and J.A.V.; Supervision, H.A.C.-B., J.A.V. and D.R.A.-G.; Project administration, H.A.C.-B. and D.R.A.-G.; Funding acquisition, D.R.A.-G.

Ethics Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The raw data supporting the conclusions of this article will be made available by the authors on request.

Funding

This research received no external funding.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

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