New records of a critically endangered shrew from Mexican cloud forests (Soricidae, Cryptotis nelsoni) and prospects for future field research.

Lázaro Guevara,Víctor Sánchez-Cordero

doi:10.3897/bdj.6.e26667

Abstract

The Nelson´s small-eared shrew, Cryptotis nelsoni (Merriam, 1895), is a critically endangered species, endemic to cloud forests in Los Tuxtlas, a mountain range along the Gulf of Mexico coast. This species is only known from the type locality and its surroundings. Here we present new records that extend its distribution approximately 7 km southeast of the type locality and report more specimens near to the type locality. We also identified climatically suitable areas for C. nelsoni using ecological niche modelling and investigated the sampling bias to identify poorly sampled areas in Los Tuxtlas. We suggest that the scarcity of records in other areas with suitable climatic conditions throughout Los Tuxtlas is a consequence of incomplete surveys. We strongly highlight the importance of continuing surveying this critically endangered shrew using more efficient sampling techniques to better understand its current distribution and conservation status. Despite all known localities occurring inside Los Tuxtlas Biosphere Reserve, deforestation and climate change still pose current and future threats to this species.

Highlights

Monitoring populations of endangered species is a priority for assessing their conservation status and establish conservation actions (Guisan et al 2006)
All the specimens displayed external characters of Cryptotis nelsoni reported previously (Cervantes and Guevara 2010, Choate 1970, Merriam 1895). They differed markedly from C. mexicanus and C. p. pueblensis in having a darker pelage and by their larger external body size, being similar to the specimens referred to C. nelsoni
Scatterplots revealed that the collected specimens were larger than C. mexicanus and C. p. pueblensis in all variables examined and completely overlaps with the previously known specimens of C. nelsoni (Fig. 2)

Summary

Introduction

Monitoring populations of endangered species is a priority for assessing their conservation status and establish conservation actions (Guisan et al 2006). Many endangered species inhabit remote areas of limited access and finding populations to determine their distribution is often a difficult task. Since the known distribution of C. nelsoni is only a few locality points around the type locality in the San Martín Tuxtlas volcano and its habitat is rapidly changing or disappearing, this species is listed as “critically endangered” by the International Union for the Conservation of Nature and Natural Resources and “under special protection” by the Mexican government (Cervantes and Guevara 2010, Woodman et al 2015). With so little known about this species, assessment of its conservation status has been based primarily on lack of knowledge

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