Friday, August 28, 2015

A reassessment of the conservation status of the Central American herpetofauna

Salamanders like this Costa Rican Bolitoglossa striata are 
more susceptible to environmental disturbances than other
amphibians. JCM
A recently published article by Johnson et al. (2015) takes a second look at the herpetofauna of Central America and its conservation needs. The authors found Mesoamerica (the area composed of Mexico and Central America) is the third largest biodiversity hotspot in the world. The Central American herpetofauna has 493 species of amphibians and 559 species of crocodilians, squamates, and turtles.
The authors use a revised EVS measure to reexamine the conservation status of the herpetofauna using the General Lineage Concept of Species to recognize species-level taxa, and employ phylogenetic concepts to determine evolutionary relationships among the taxa.
Since the publication of Conservation of Mesoamerican Amphibians and Reptiles, in 2010, 92 species of amphibians and squamates have been described, resurrected, or elevated from subspecies to species level, and one species of anuran has been synonymized. The herpetofaunal diversity of Central America is comparable to that of Mexico, a significant finding because the land area of Mexico is 3.75 times larger. The number of amphibian species is 1.3 times greater in Central America, whereas the number of species of turtles, crocodilians, and squamates is 1.5 times greater in Mexico. Endemicity is also significant in Central America (65.6% of amphibians, 46.5% of turtles, crocodilians, and squamates), with a combined average of 55.6%.
The authors regard the IUCN system as expensive, time-consuming, and behind advances in systematics and over-dependent on the Data Deficient and Least Concern categories. Conversely, the EVS measure is economical, it can be applied when species are described, is predictive, simple to calculate, and does not “penalize” poorly known species.
The EVS analysis of amphibians demonstrates that on average salamanders are more susceptible to environmental deterioration, followed by caecilians, and anurans. Among the remainder of the herpetofauna, crocodilians are the most susceptible and snakes the least, with turtles and lizards in between.
Biodiversity decline is an environmental problem of global dimensions, comparable to the more commonly publicized problem of climate change. Both of these environmental super-problems exist because of human action and inaction, exacerbated by humanity’s anthropocentric focus.

Citation

Johnson, J. D., Mata-Silva, V., & Wilson, L. D. (2015). A conservation reassessment of the Central American herpetofauna based on the EVS measure. Amphibian & Reptile Conservation, 9(2), 1-94.

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