Texas takes steps to halt spread of fungus lethal to bats
FORT WORTH, Texas -- Texas officials are considering closing the state's caves out of fear that a deadly fungus associated with the growing number of bat deaths in the Northeastern United States may spread to this part of the country.
White-nose syndrome, so named because the white fungus appears on bats' noses, has spread rapidly throughout the Northeast since it was first discovered in New York in the winter of 2006-07. It hasn't been discovered in Texas, but it has already reached 10 states, including Oklahoma.
While many people may be creeped out by bats, the nocturnal creatures are considered crucial to the agricultural community. For Texas, home to 33 bat species, widespread deaths could be devastating. A 2007 study found that bats help control pests that cost U.S. farmers $1 billion annually.
"At this point we're considering whether we should be closing caves on state-owned lands," said John Young, a Texas Parks and Wildlife mammalogist. "We have a number of them on state-owned lands."
The U.S. Forest Service has already closed caves and old mines from Oklahoma to Maine. But the agency has no caves in its national forests or grasslands in Texas, spokeswoman Gay Ippolito said.
The situation has become serious enough that two subcommittees of the U.S. House Natural Resources Committee are planning to address it in a hearing Thursday.
Last week, Bat Conservation International hosted a conference in Austin, Texas, to prepare for the hearings and bring experts from across the country to discuss the subject.
"One of the lead scientists at the meeting said this is the worst wildlife crisis documented in North America in the last century," said Merlin Tuttle, the group's founder, who was its president/executive director until Sunday.
"With its rate of spread it could certainly be in Texas within two years," Tuttle said. "We just don't know. We do know it is something that is certainly killing 95 to 100 percent of the bats it comes in contact with."
A 2006 report in the scientific journal Frontiers in Ecology and the Environment determined that bats provided a $1.7 million benefit to the eight South Texas counties in their study area.
The only glimmer of hope for Texas is that Mexican free-tailed bats, the predominant species in Texas, is migratory and doesn't hibernate in winter. So far, all the species that have had large die-offs hibernate in colder climates in the Northeast.
White-nose syndrome appears to lie dormant during the warmer summer months and attacks bats during their winter hibernation, Tuttle said, but there are many unanswered questions.
"We don't even know for sure if the fungus itself is the problem or symptom of the problem," Tuttle said. "We do know that bats with this fungus on them arouse far more than normal during normal hibernation. The bats are dying in an emaciated status. The fungus is a strong suspect, but we need to confirm it is the problem. Once we confirm it, we need to learn how it is transmitted - and once it is transmitted, how it attacks the bats."
Though it is believed that the fungus is transferred from one bat to another, there is some concern that researchers' clothing and equipment could spread it from cave to cave. That is why caves have been closed across the country.
Bracken Cave, outside of San Antonio, is home to the largest Mexican free-tailed bat colony in the world. Its owner, Bat Conservation International, restricts access: The public can view bat emergences but cannot enter the cave.
Experts say the public can safely view bat emergences at popular sites like Bracken Cave and the Congress Avenue Bridge in downtown Austin. At the Eckerd James River Cave in the Hill Country, the Nature Conservancy of Texas allows escorted viewings of the emergences from April through October.
Visitors do not enter the cave and researchers haven't been inside for at least four or five years, said John Herron, the Texas chapter's director of conservation.
But Tuttle said the fear is that some researcher will inadvertently bring the fungus to Texas.
"The big worry is while scientists are trying to find a solution, someone from an infected area will bring spores from the fungus to a cave in Texas from their caving gear or even on their human bodies," Tuttle said. "It could get a big hopscotch leap, which would be terrible. We need every day we have to find a solution before it arrives."
Copyright 2009 Miami Herald Media Co.
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