Ecologists and biologist who study the world’s flora and fauna have been reporting a species decline amongst amphibians for over a decade or more. This decline has been attributed to a combination of habitat loss and diseases (a fungus pandemic, a virus). A 2007 paper (Becker, et al) made a case for “habitat splitting” wherein certain Brazilian, Amazon frog species that are born in water, but then occupy land ecosystems as adults, are “cut off” from making this transition, due to human road building and development.
And yet, despite this trend, there remain biological (or biodiversity) “hot spots” around the globe in which a great many amphibian species are found to be thriving in the same ecosystem. In some cases, such hot spots offer potentially hundreds of new species for discovery and analysis. One such hot spot is the island of Madagascar. It is an “Eden” for amphibians.
A recent “integrative” inventory and genetic sequence analysis of native amphibian species (Vieites, et al, recently reported in the Proceedings of the National Academy of Science) looked at over 2,800 specimens from 170 locales on the island (which is located just off the S.E. coast of Africa and is the world’s 4th largest island) demonstrated “an extreme proportion of amphibian diversity.” Previous inventories of Madagascan amphibians tallied around 244. But according to the research team, this is a significant under-estimation; the total number of species of this class of animals is at least 373 and possibly as many as 465. Most of these new species have yet to be named.
The team asserts, based upon their results, that amphibian diversity world-wide is being under-estimated at an “unprecedented level”. The researchers hope that their “integrative taxonomic survey” approach to specimen analysis will be adopted by other scientists to improve their inventory counts and also buttress other biodiversity preservation initiatives through helping scientists and policy makers prioritize conservation efforts within these hot spots.
Tracking the patterns of biodiversity of such amphibians–a grouping that includes frogs and salamanders–is difficult for many reasons: the remoteness of the locales, the extreme conditions, local laws, and sometimes even because of human conflict. This latter reason has recently (March, 2009) become the main obstacle for scientists working on Madagascar, see my earlier post: Madagascar Coup Threatens Bio-Diversity “Hot Spot”)
map image credit: Vardion of wikipedia.org – GNU
About Michael Ricciardi
The hyperlink for the Proceedings of the National Academy of Sciences is incorrect. The correct website for the journal is http://www.pnas.org