Across the globe a vanishing act is about to occur. Almost 800 species are at risk of imminent extinction.
A new map produced by scientists working with the Alliance for Zero Extinction—a coalition of global and regional biodiversity conservation organizations—identifies areas where threatened species could soon be wiped from the planet. The global survey of endangered species distribution will be featured in a paper to be published in the December 20th issue of the Proceedings of the National Academy of Science.
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"We assembled this list with pretty stringent criteria, so all the members [species on the list] are really the tip of the iceberg—on the leading edge of the extinction episode we are in right now," said Taylor Ricketts, lead author of the paper and director of conservation science for the World Wildlife Fund.
Five major taxa—mammals, birds, selected reptiles, amphibians and conifers—were examined. To avoid classification and geographic bias, taxa were chosen for the study only if they had been comprehensively assessed by the World Conservation Union (IUCN). Of the 1.9 million described species in the world, only about 40,000 of them have been cleared for inclusion on the IUCN Red List of Threatened Species, the benchmark of conservation-status for a species. The plights of some species on the list, like the whooping crane, have already garnered much public attention. But many species, like the Ruo River screeching frog of Malawi, the gloomy tube-nosed bat of Indonesia or Hotson's mouse-like hamster of Pakistan are less well known.
"There are a lot of reasons the members on this list are threatened," said Ricketts, "but the one that unites them all is a very small amount of remaining habitat."
In this survey, a site was designated a hotspot of imminent extinction if it is the only location where an endangered or critically endangered species lives (according to the 2004 Red List). The map of hot spots showed alarming new trends in extinction. In the past, most extinctions have taken place in island ecosystems; this extinction episode is occurring in, as Ricketts calls them, "continental storehouses of diversity."
"What we're seeing is a geographic shift," said Michael Hoffman, a biologist for Conservation International. "A very large number of extinctions are now taking place or about to take place on continental land masses."
The change in extinction patterns is taxonomic as well as geographic. Historically, most chronicled extinctions were of bird species. Now amphibian species—which tend to be habitat specialists and are often susceptible to disease—are most prone to extinction. Amphibians have long been identified as indicator species that can give early warnings of environmental degradation.
"Our imprint on the Earth is just growing day by day so habitat loss in the continents is actually beginning to catch up with a broad group of species," said Hoffman.
Identifying endangered habitats gives us an opportunity to halt the loss of biodiversity within them. Only one-third of habitats identified in the study are currently legally protected.
"The immediate, kind of 'no-brainer' thing to do for each of these [threatened species] is to protect legally, and formally, the habitat that remains," said the WWF's Ricketts, who hopes that the paper will guide conservation groups, showing them where to focus their species-protection efforts.
Hoffman is optimistic that, if habitats become regulated, a lot of the species on this list will be rescued. "There are so many examples where species have declined to very low numbers and we still managed to rescue them," he said. "Protected areas remain fundamentally the most important and primary means of ensuring species persistence."