|Gray bats fly out of a cave in Baxter County. White-nose |
syndrome, which has killed millions of bats, is moving west
but has yet to be observed in Arkansas. (Kevin Pieper)
The infectious disease called white-nose syndrome has infected millions of bats in 16 states, and the fungus responsible for the disease has been identified in three states, including Missouri and Oklahoma. The disease is named for the white fungus that appears on infected bats.
“It’s moving this way,” said Erin Leone, an endangered species biologist with the Arkansas field office of the U.S. Fish and Wildlife Service at Conway.
In north-central Arkansas, biologists with the Arkansas Game and Fish Commission are monitoring caves and have sent off some bats for testing, Leone said.
The disease first was spotted in Albany, N.Y., in 2006 and spread rapidly across the eastern United States. Confirmed cases of white-nose syndrome have been documented in Ohio, Indiana, Kentucky and Tennessee, according to information from the U.S. Fish and Wildlife Service. So far, no cases have been found in Arkansas.
During the 2009-2010 winter season, suspected cases of white-nose syndrome were found in Oklahoma and Missouri, said Blake Sasse, nongame mammal/furbearer program leader with the Arkansas Game and Fish Commission. The cases were based on positive tests ofGeomyces destructans — the fungus responsible for white-nose syndrome — which were identified on a few of the bats that were sampled, said Mike Armstrong, southeast region white-nose syndrome and bat recovery coordinator with the U.S. Fish & Wildlife Service. But biologists and researchers have not confirmed white-nose syndrome, and the fungus has not been found on any additional bats, he said. While biologists have no reason to believe the tests are incorrect, there is a possibility the test results may have been false positives, he said.
Biologists originally estimated that 1 million bats have died from white-nose syndrome, but now, estimates are between 5.7 to 6.7 million bats, according to information the U.S. Fish and Wildlife Service released last month.
Bat species affected by white-nose syndrome include the big brown bat, the eastern small-footed bat, the Indiana bat, the little brown bat, the northern long-eared bat and the tricolored bat, according to the U.S. Fish and Wildlife Service. The Geomyces destructans fungus has been detected in the cave bat, the endangered gray bat and the southeastern bat, according to the agency.
While white-nose syndrome is deadly, scientists do not know exactly what causes infected bats to die. One theory is the fungus irritates hibernating bats, causing them to wake up and use up fat reserves, Leone said. Another theory is the fungus in the wing membrane causes the bats to lose water and dehydrate, she said.
White-nose syndrome is a serious threat to bat populations. Female bats are slow reproducers and typically give birth to one pup a year, making them more vulnerable to extinction. Bats also are an important part of the ecosystem, in part because they are pest controllers: One bat can eat as many as 3,000 insects a night, biologists say.
An estimated 400,000 to 500,000 endangered gray bats are hibernating in Arkansas this winter, Sasse said. Last summer, about 70,000 gray bats were in female maternity colonies in the state, he said.
There are several ways the public can help inhibit the spread of white-nose syndrome.
The public is encouraged to stay out of caves year-round, because humans can spread the disease through dirt and mud from their clothing, boots and gear. Those who cave should decontaminate their clothes and gear. All federal and state caves remain closed to the public due to the potential spread of white-nose syndrome, with the exception of Blanchard Springs Caverns in Mountain View, Leone said.
Those who find a large number of dead bats are encouraged to call the Arkansas Game and Fish Commission or the U.S. Fish and Wildlife Service. Property owners also can place bat houses on their property to provide a place for bats to live in the summer, which could lead to healthier bats and give them a better chance of surviving disease during winter, Armstrong said.
For information about the syndrome and research, visit the U.S. Fish and Wildlife Service website at www.fws.gov/ whitenosesyndrome.
Source: Baxter Bulletin