By Alister Doyle
OSLO (Reuters) - Animals living in patches of rainforest cut off from bigger expanses of jungle by farms, roads or towns are dying off faster than previously thought, according to an academic study published on Tuesday.
"We uncovered a staggering rate of local extinctions," the British and Brazilian researchers wrote in the online science journal PLOS ONE.
They visited 196 fragments of what was once a giant, intact forest in eastern Brazil on the Atlantic coast, now broken up by decades of deforestation to make way for agriculture.
Each isolated forest patch, ranging from less than the size of a soccer pitch to more than 5,000 hectares (12,000 acres), had on average only four of 18 types of the mammals the experts surveyed, including howler monkeys and marmosets.
White-lipped peccaries, similar to pigs, "were completely wiped out and jaguars, lowland tapirs, woolly spider monkeys and giant anteaters were virtually extinct," the British and Brazilian scientists said of their findings.
Normal estimates of declining wildlife numbers, based on the size of isolated forest fragments, predicted higher survival rates, it said. But they had underestimated continuing human pressures such as hunting and fires.
"This is bad news for conservation," Professor Carlos Peres, of Britain's University of East Anglia, told Reuters. Many animals had vanished even in what seemed big areas of forest with intact tree canopy, he said.
The rate of species loss in the area studied - the Atlantic Forest region which covers 250,000 sq km (95,000 sq miles), the size of Britain or the U.S. state of Michigan, was likely to be mirrored in other countries such as Indonesia, Ghana or Madagascar, Peres said.
PLEA FOR PARKS
The scientists urged better conservation. In Brazil, animals survived best in five forest remnants that were protected as parks. "This paper is a very big positive endorsement of more protected areas," Peres said.
Measures to place an economic value on forests could help, for instance by making them part of a fight against climate change, he said.
Forests absorb carbon dioxide, the main greenhouse gas, as they grow and release it when they burn or rot. Between 12 and 20 percent of man-made greenhouse gas emissions, most of which come from burning fossil fuels, are caused by deforestation.
Almost 200 nations are looking into ways to protect forests through a U.N. program called REDD (Reducing Emissions from Deforestation and forest Degradation) that would put a price on carbon stored in trees in developing nations, for example by bringing forests into carbon trading systems.
Peres said that "degradation" in U.N. jargon referred mainly to logging but should be expanded to cover threats to wildlife. "My mission is to put wildlife and biodiversity into that second 'D' of REDD," he said.
(Reporting By Alister Doyle; Editing by Robin Pomeroy)