3,000 amphibians, 160 land mammals remain undiscovered?that is if they don't go extinct first

[Frog News]

Mongabay News (California, USA) May 18th, 2011 12:39 PM: 3,000 amphibians, 160 land mammals remain undiscovered?that is if they don't go extinct first

Remote little-explored rainforests probably harbor the majority of undiscovered amphibians and land mammals according to a new study in Proceedings of the Royal Society B. The study calculated that it's likely 33% of the world's amphibians and 3% of terrestrial mammals still remain unknown. However, the paper also found that these undiscovered species are likely in worse peril of extinction than already-described species.

"We show that even after 250 years of taxonomic classification, about 3050 amphibian and at least 160 land mammal species remain to be discovered and described," the researchers write. They did not calculate estimations for other taxa.

Estimates were arrived at by using a mathematical model, incorporating known amphibian and mammal species, the year in which species were discovered, and the region it inhabits.

Not surprisingly, new amphibians and land animals are most likely to be discovered in tropical rainforests, according to the paper. Regional hotspots for new species include the Neotropics, such as the Amazon and the Atlantic Forest; the African tropical regions like the Congo; and rainforests in Malaysia and Indonesia.

The more remote and untouched the forest the likelier it is that it harbors unknown species.

"The proportion of undescribed species increases with decreasing human footprint in tropical forest biomes," the study explains. "This could be owing to the fact that tropical forests with low human footprint are less well-explored compared to areas with a higher level of human impact."

However, authors also say that greater human impact may mean that a number of unknown species have already been pushed to extinction, making discovery impossible.

The paper also found that recently discovered species (such as one found in 2007 versus 1798) were more prone to be in danger of extinction, implying that undescribed species also have a higher chance of being globally imperiled.

"Many of the undescribed species in these two groups are likely in danger of extinction and could well disappear before they are discovered, especially given the high rates of habitat conversion in tropical forests," the authors write, adding that "this is consistent with predictions that a large proportion of today’s undescribed species may go extinct without ever being recorded."

The researchers conclude that "the perfect storm for biodiversity loss is upon us. Universities and funding agencies have weakened their support for taxonomic exploration and research, with little prospect of reversing this trend. Meanwhile, the very biomes that likely harbor the greatest number of undescribed species are being altered in ways that will drive many of these species to extinction."

They recommend that efforts be made to rapidly place remote, unexplored areas in the tropics under protection in order to preserve the world's 'cryptic biodiversity' for future discovery.

CITATION: Xingli Giam, Brett R. Scheffers, Navjot S. Sodhi, David S. Wilcove, Gerardo Ceballos, and Paul R. Ehrlich. Reservoirs of richness: least disturbed

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