WASHINGTON (CN) - Environmentalists are outraged that though 99 percent of Northern long-eared bats have died of white-nose syndrome in their core habitat, the federal government has listed the species as threatened rather than endangered.
The Center for Biological Diversity sued the U.S. Fish and Wildlife Service on Thursday in D.C. Federal Court, challenging the rule.
Fish and Wildlife listed the Northern long-eared bat as "threatened" under the Endangered Species Act on April 2, and exempted the rule from some ESA protections.
Fish and Wildlife defended its exemptions by saying they have timing restrictions to protect bats when they are most vulnerable, such as when pregnant, and before the pups can fly. The restrictions can be lifted, with Fish and Wildlife's permission.
White-nose syndrome has killed as many as 99 percent of the bats in their core range, according to the Center for Biological Diversity, which petitioned to list the bat as endangered in 2010.
Scientists still have not figured out how to protect bats from the fungus, which wastes the bats while they hibernate in caves, killing them outright or making them so weak they cannot forage for food when they wake up.
The Northern long-eared bat is the hardest hit by the fungus, possibly because they hibernate not in open caves, but tucked tightly into crevasses sometimes with only nose and ears showing, according to the Center for Biological Diversity.
Bats are important pollinators, particularly of fruit crops, and pay a major role in controlling populations of insects, particularly mosquitoes.
The small bat forages along wooded hillsides and ridgelines in large blocks of mature, interior forest, so forest fragmentation, logging and clearing trees for agriculture and development are major threats to the species.
Other threats include badly sited wind-energy projects, which kill bats that fly into them; environmental contaminants such as pesticides and fracking wastewater; other forms of habitat destruction, such as mining; and direct human disturbance.
Humans who wake the bats during hibernation with changes in light and sound due to commercialization, recreation or study, can cause bats to arouse more frequently, causing premature energy depletion and starvation.
Fish and Wildlife proposed changing the bat's status from endangered to threatened in January, and issued its final rule on April 2.
Fish and Wildlife said that some populations of the bat have not been devastated by the disease, and discussed when the bat is likely to go extinct, in explaining its listing determination. It said that white-nose syndrome has not appeared in some places where the bats live.
The Center for Biological Diversity said Fish and Wildlife's refusal to protect the bat as endangered was unwarranted.
"The only thing that has changed since the initial recommendation is that more bats in more states have died," the Center said in December, when the reduced level of protection was anticipated, citing Eastern Michigan University Professor Allen Kurta
The listing becomes effective on May 4.
The agency is accepting comments on the interim exemptions until July 1.