Extinction risk assessment of the endemic terrestrial vertebrates in Mexico

Abstract

An increasing number of species at risk raise concerns worldwide. While global assessments provide a comprehensive framework, national species conservation status is needed to provide specific policies. The IUCN Red List and the Mexican Norm (MER) methods were used to assign risk categories for 310 endemic species of terrestrial vertebrates at national and ecoregion levels. We used ecological niche models projected as species potential distributions, and refined species extant distributions including only remnant suitable habitat, to assess species risk assignments for Criterion A and B (IUCN Red List), and Criterion A, B, C, and D (MER). Of the total number of species, the IUCN Red List and MER report 71 and 155 species at risk, respectively. Our assessment assigned a risk category to 38 and 299 species, respectively. The discrepancies in the number of species between our proposal and the IUCN Red List and MER are striking and probably due to shortcomings of deficient information or expert opinion of species, standardization between methods, and the number and particular characteristics of criteria. Species occurring in the Mexican Transvolcanic Belt, the Great Plains and the Yucatan Peninsula ecoregions were at higher extinction risk than species occurring in the Mexican deserts, the Mexican High Plateau, the Southern Sierra Madre and the Western Sierra Madre ecoregions. Our proposal of using species potential and extant distributions models facilitates frequent species assessments, as conditions of risks fluctuate over time, and contributes to designing national and regional conservation programs of species and populations at risk.