Washington - Deadly white-nose syndrome is threatening to make one insect-eating species of bat extinct, at least regionally, US researchers reported on Thursday.
The infection is spreading quickly across the Northeastern United States and Canada and is likely to cause the regional extinction of the little brown myotis bat, the researchers report in the journal Science.
It had been one of the most common species of bats in North America and was considered beneficial because of its appetite for mosquitoes, flies and other pests.
"This is one of the worst wildlife crises we've faced," said Winifred Frick of the University of California, Santa Cruz.
"Bats affected by this disease are all insect-eating species, and an individual bat can consume their body weight in insects every night, including some consumption of pest insects."
The syndrome, linked to a fungus that spreads among bats as they hibernate, affects at least seven species, the researchers said.
It was only identified four years ago, in bats nesting in caves near Albany, New York. Since then, more than a million of the flying mammals have died as far afield as Tennessee and Oklahoma.
"The loss of so many bats is basically a terrible experiment in how much these animals matter for insect control," Frick said.
The fungus kills in an insidious way, making the bats restless as they try to hibernate. As they fidget, they burn up their reserves of fat. The researchers estimate that 73 percent of animals in a colony die once the infection reaches them.
"Given the rapid geographic spread of this fungus over the past four years, we can expect that white nose syndrome will adversely affect bat species that form some of largest hibernating bat colonies in the US, including two federally listed endangered species that occur mostly in the Midwestern states," Boston University biologist Thomas Kunz said in a statement.
Some research has suggested that people exploring caves have helped spread the fungus so quickly. It also appears to spread from bat to bat, and many regional and local authorities have closed caves to public access when the infection pops up.
Bats appear to have little or no immunity to the cold-loving fungus, called Geomyces destructans, the researchers said. It covers their muzzles and invades their skin, according to the US Fish and Wildlife Service.
"Such a severe population decline, especially if the disease spreads farther south and west of its current distribution in eastern North America, may result in unpredictable changes in ecosystem structure and function," Kunz and Frick's team concluded. - Reuters