Group aims to stop spread of deadly bat disease

A mysterious disease that has ravaged bat populations in the northeastern United States is threatening to spread West, potentially triggering a mass die-off of the flying mammals, which help control populations of insects that can damage agricultural crops, a conservation group said.

The Center for Biological Diversity sent letters this week to state wildlife officials across the country, urging them to consider closing state-owned caves to the public to prevent the spread of white-nose syndrome.

More than a million hibernating bats have died since the disease was first documented in upstate New York in 2006. It has spread around the Northeast and has been detected as far south as Virginia and now as far west as Missouri.

"We are in the position of potentially finding out what an important role bats play through their loss," said Mollie Matteson, an advocate with the conservation group. "Losing bats is probably going to upset the ecological balance."

The fungus linked to the syndrome appears to thrive in cold, moist caves and affects hibernating bats.

Six bat species are known to be affected by the fungus, including the little brown bat and the federally protected Indiana bat.

In Missouri, officials announced Thursday they were temporarily closing most caves in state parks and historic sites to help contain the disease. Caves are also being closed in Iowa, Indiana, Illinois and Tennessee.

At Mammoth Cave in Kentucky, visitors are warned not to wear gear into the cave that has been used outside the Mammoth area.

No caves have been closed in the western U.S. because of the syndrome.

The Tucson, Ariz.-based group's letter said closing state-owned caves and educating the public about white-nose syndrome could minimize the spread of a fungus associated with the disease.

Humans can transmit the fungus through contaminated boots and clothing or caving equipment, the group said.

New Mexico has implemented restrictions on equipment that has been used in the eastern U.S. as a precaution, said Jim Stuart, a mammalogist with the New Mexico Department of Game and Fish and a member of the Western Bat Working Group.

While there are some hibernating species in New Mexico, the state's most famous bats - the Mexican free-tailed bats of Carlsbad Caverns National Park - migrate south for the winter rather than hibernate.

Carlsbad, one of the more famous cave systems in the Southwest, draws around 430,000 visitors annually, and the bats are one of the park's main draws. Every evening, an enormous cloud of bats emerges from the main cave to go hunting for insects.

No one knows for sure whether the fungus can affect Mexican free-tailed bats, Matteson said.

"It's just one of those things where the consequences are so dire, why not take at least some measures to reduce the risk," she said.