LONDON America's bats are dying in their hundreds of thousands due to a mysterious illness called white-nose syndrome, and efforts to save them could prevent billions of dollars in agricultural losses, scientists say.
In a paper published in the journal Science, bat researchers estimated that a single colony of 150 brown bats in the U.S. state of Indiana eats around 1.3 million pest insects a year, and that the value of such bats to agriculture may be around $22.9 billion a year.
They criticized a lack of funds and efforts to save the bats and to find out more about what is causing their widespread population decline. The current "wait-and-see" approach is unacceptable, they said.
"Bats are among the most overlooked, yet economically important, non-domesticated animals in North America, and their conservation is important for the integrity of ecosystems and in the best interest of both national and international economies," the scientists, led by Justin Boyles of the University of Pretoria in South Africa, wrote in the journal.
"The life histories of these flying, nocturnal mammals -- characterized by long generation times and low reproductive rates -- mean that population recovery is unlikely for decades or even centuries, if at all."
The deadly white-nose infection is spreading quickly across the Northeastern United States and Canada, and a study published last year suggested the disease is likely to cause the regional extinction of the one species of bat known as little brown myotis bat.
The syndrome, linked to a fungus that spreads among bats as they hibernate, affects at least seven species, experts say. It was only identified in the United States 2006, in bats nesting in caves near Albany, New York, and since then more than a million of the flying mammals have died.
"This disease is burning through our bat populations like a five-alarm fire," said Mollie Matteson, a conservation advocate at the Center for Biological Diversity in Ohio.
In a telephone interview, Boyles said the researchers aim was to drive home the importance of protecting bats -- animals he said were often undervalued by the public and policymakers.
"A lot of people say 'why should we care about bats?," he explained. "So our goal is to try and emphasize how important they are ecologically and economically," he said.
The scientists said the rising number of wind turbines in the United States and Europe were another major threat to bats. Thousands of dead bats have been found near wind farms, and some scientists believe sudden changes in air pressure close to wind turbines can cause the lungs of the tiny creatures to collapse.
"Solutions that will reduce the population impacts of white-nose syndrome and reduce the mortality from wind-energy facilities are possible in the next few years," they wrote. "But identifying, substantiating, and applying solutions will only be fueled...by increased and widespread awareness of the benefits of insectivorous bats among the public, policy-makers and scientists.
(Editing by Paul Casciato)