Researchers Pinpoint Mammal Extinction Hotspots

Conservationists have created a map of potential extinction hotspots, highlighting where humans are set to trigger dramatic declines in animal populations over coming decades.

The map pinpoints 20 areas, ranging from the Siberian tundra to the Patagonian coast, where mammals are particularly at risk from human activity, such as deforestation and hunting. The survey was designed to reveal areas where land mammals are thriving but are expected to suffer disproportionately from expected increases in the local human population and changes in habitat.

The arc of fertile islands that runs from Indonesia to the South Pacific, the Bahamas, and the vast expanses of Greenland were among the most fragile regions marked, with the musk ox, Seychelles flying fox, brown lemur and North American reindeer topping the list of threatened species.

By constructing the map, the scientists hope to help conservation organizations identify regions where they can prevent declines before it is too late.

"There are still large areas of the world that are reasonably intact, where species are doing well, but where human impact is increasing," said Marcell Cardillo, a biologist at Imperial College London.

"We wanted to determine which areas are going to be the most sensitive to human impact so we can prioritize conservation projects. Conservation is a crisis discipline. Because there are so many species on the verge of extinction, that’s where most of the effort goes."

The map, published today in Proceedings of the National Academy of Sciences, was created by assessing the known extinction risk of different species and how resilient they are to human activity. Typically, large animals, those with low reproductive rates and those whose populations are confined to small areas are most at risk. Larger animals suffer largely because they tend to be targeted by hunters.

The researchers studied nearly 4,000 mammals and compared the list with data on trends of human activity in regions where the mammals are found. They then pinpointed which regions would become conservationists’ future battlegrounds.

The map identifies islands of concern, which are home to more than a thousand mammal species. New Guinea, the Melanesian and Indian Ocean islands are particularly at risk because of expected surges in human population.

In many of the regions identified, mammals are thriving, but their heightened sensitivity to the disruption human activity will bring could see some of the species leapfrog those known to be on the road to extinction. "We can see this leapfrogging happening now, for example with the Guatemalan howler monkey, which was classified as being on the ‘least concern’ list in 2000 but which moved to the endangered list in 2004," said Dr Cardillo.

"We hope conservationists will use our findings to pre-empt future species losses rather than concentrating solely on those species already under threat," he added.

John Fa, director of conservation science at the Durrell Wildlife Conservation Trust, said that conservation organizations have traditionally focused too little on preventive projects. We need to pick up on what areas are going to be a problem in the future."

He added: "We can bring in preventive measures to protect habitats and, with climate change on the way, the spots we need to be protecting may well change, so this is not going to be easy."