Amphibian extinction may be worse than thought
Amphibian extinction may be worse than thought
mongabay.com
October 31, 2007
Amphibian extinction rates may be higher than previously thought, according to new DNA analysis that found more than 60 unrecognized specie in the Guiana Shield of South America.
Writing in PLoS ONE, a team of scientists warned that the number of amphibian species have been greatly underestimated. They estimate that there may be 170 to 460 unrecognized frog taxa in Amazonia-Guianas region alone and up to a total of 4400 species in South America.
The researchers say their work shows the urgent need to catalog biodiversity before it disappears.
“As a consequence of the underestimation of the number of frog species, the global amphibian decline detected especially in the Neotropics may be worse than so far realised,” write the authors. “Indeed, we cannot know how many “species” instead of “populations” have already disappeared or are disappearing, and the situation is particularly acute in the tropics.”
A previously unknown species of toad, possibly of the Atelopus genus, discovered during a Conservation International-led expedition in Suriname’s Nassau plateau. Atelopus toads have been particularly affected by the deadly chytrid fungus. Photo © Paul Ouboter |
“The rapid identification and recognition of new species may exacerbate an organism’s threat status because it can result in the subdivision of a once widespread species into numerous species, each with a smaller and, hence, a more precarious distribution. Nevertheless, it is obviously better to know the state of biodiversity threat than to be ignorant of the mammoth changes in global amphibian diversity that we are witnessing,” the continue.
Amphibians — cold-blooded animals that include frogs, toads, salamanders, newts and caecilians — are dying in huge numbers all over the planet: the Global Amphibian Assessment, a comprehensive status assessment of the world’s amphibian species, reports that one-third of the world’s 5,918 known amphibian species are classified as threatened with extinction and more than 170 species have likely gone extinct since 1980. While scientists have yet to find a smoking gun, climate change, pollution, and the emergence of a deadly and infectious fungal disease, which has been linked to global warming, are the leading suspects for the observed decline.
Citation: Fouquet A, Gilles A, Vences M, Marty C, Blanc M, et al (2007) Underestimation of Species Richness in Neotropical Frogs Revealed by mtDNA Analyses. PLoS ONE 2(10): e1109. doi:10.1371/journal.pone.0001109
Related articles
Scientists find treatment for killer frog disease
(10/29/2007) New Zealand scientists have found a treatment for a disease blamed for the death of millions of amphibians worldwide, according to a report from BBC News. However, at best, the cure would only be applicable to captive populations. The disease is killing many amphibians in apparently pristine habitats.
Two new species of salamander discovered in Panama
(9/9/2007) Scientists have discovered two new species of salamanders from the mountainous Costa Rica-Panama border region. The findings, published by David B. Wake, Jay M. Savage, and James Hanken in the journal Copeia, push the number of salamanders known in the region to 24, making it a hotspot in terms of salamander biodiversity.
New poison frog species discovered in Colombia
(8/28/2007) Scientists have discovered a previously unknown species of poison frog in a remote mountainous region in Colombia. The tiny frog has been dubbed the “golden frog of Supata” and lives only in a 20 hectare area in Colombia’s Cundinamarca region.
Scientists meet in Hungary to discuss saving dying frogs
(8/27/2007) Scientists are meeting this week in Budapest, Hungary to discuss last-ditch efforts to save the world’s most threatened frogs from extinction.
 |
Forest disturbance reduces biodiversity in the Amazon rainforest
(7/2/2007) Two new studies in the Amazon rainforest show that plantation forests and second-growth forests have lower species counts for butterflies, reptiles, and amphibians than adjacent primary forest areas. The research has important implications for conservation of tropical biodiversity in a world where old-growth forest is increasingly replaced by secondary forests, industrial plantations, and agricultural landscapes.
Global warming may be key factor in frog deaths
(5/30/2007) Three papers published in this week’s issue of the journal Nature debate the proximate causes for the global decline of amphibians, but nonetheless reveal mounting concerns among scientists over the continuing disappearance of frogs, salamanders, and their relatives.
 |
Bad news for frogs; amphibian decline worse than feared
(4/16/2007) Chilling new evidence suggests amphibians may be in worse shape than previously thought due to climate change. Further, the findings indicate that the 70 percent decline in amphibians over the past 35 years may have been exceeded by a sharp fall in reptile populations, even in otherwise pristine Costa Rican habitats. Ominously, the new research warns that protected areas strategies for biodiversity conservation will not be enough to stave off extinction. Frogs and their relatives are in big trouble.
