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Salamanders like this Costa Rican Bolitoglossa striata are
more susceptible to environmental disturbances than other
amphibians. JCM
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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.