Bat disease affects CO spelunkers

DENVER I As Indiana and North Carolina in the last week announced finding white-nose syndrome in bats in their states, the Colorado Division of Wildlife is stepping up monitoring efforts here at home. The agency is inspecting bat hibernation sites this winter looking for the presence of a deadly fungus that leads to massive bat die-offs.
“Bats are an important yet under-appreciated part of our world and this threat is something we should all be worried about,” said Tina Jackson, a species conservation coordinator for the Division of Wildlife.
White-nose syndrome, which is caused by a fungus known as Geomyces destructans, is responsible for large-scale bat die-offs in the Eastern United States. In the four years since it was first discovered, white-nose syndrome is responsible for the death of more than one million bats.
White-nose syndrome is named for the white, powder-like material seen on the nose, ears and wings of infected bats. It is believed to have originated in Europe. Some bats in Europe, subjected to the fungus for many years, may have developed immunities that bats in North America don’t possess.
Without any natural protections, white-nose syndrome can wipe out 95 percent of a bat colony in a couple of years. It has been predicted that white-nose syndrome could eliminate little brown bats in the northeastern U.S. within 16 years.
White-nose syndrome has not been found in Colorado. Since being first documented in 2007 in a cave in New York, white-nose syndrome has spread to 16 states and two Canadian provinces.
In 2010, a cave in northwestern Oklahoma and less than 200 miles from the Colorado border tested positive for the fungus. Scientists speculate that the fungus jumped from Europe to the U.S. through human transmission. They also believe that a large jump from the East Coast to a cave in Oklahoma was probably someone who had explored an infected cave and then traveled west with the fungus on clothing or equipment.
“Once the fungus arrives in an area, it can spread quickly as bats move,” said Jackson. “But the fungus makes the biggest leaps in distance when it moves because of human activity.”
Scientists are still learning about white-nose syndrome but it is believed to take advantage of bats during hibernation. The immune system of a hibernating bat effectively shuts down, allowing the fungus to become established.
Bats in colonies infected with white-nose syndrome seem to arouse from hibernation more frequently than uninfected populations, possibly because of irritation, hunger or thirst. The increased number of arousals from hibernation quickly depletes the bat’s fat reserves and results in starvation. The fungus also causes damage to the wings affecting the health of the bat and perhaps compromising the ability to fly and capture insects.
Colorado is home to at least 18 species of bats, 13 of which are believed to hibernate in the state. Bats that migrate to warmer climates for the winter are not believed to be effected by white-nose syndrome. All the bat species found in Colorado are insect eaters, in some cases eating thousands of insects a night. This diet of night-flying insects makes bats important for the control of agricultural and human pests. Bats are also important to the cave environments they roost in, bringing energy into these mostly closed systems in the form of their guano.
The public is asked to not disturb hibernating bats and to respect cave closures. The U.S. Forest Service has closed all caves on its lands in Colorado and several surrounding states in order to prevent the spread of the fungus. While the public is asked to avoid going near bat caves, people are being asked to report if they see any signs of white-nose syndrome.
Signs include:
• Bats moving to the openings of the hibernation site during the winter.
• Bats leaving hibernation sites in the winter, especially on cold days.
• Bats with a white powder-like material on their nose, ears or wings.
• Dead bats.
The Division of Wildlife would also like to know of any sites, especially in eastern Colorado, that have hibernating bats so biologists can include them in the monitoring effort.
“Information from the public will be critical to our effort this year,” said Bob Davies, wildlife disease manager.
Members of the public who see any active or dead bats this winter are asked to report that information to a special phone line (303)291-7771 or e-mail [email protected]. Because bats also can be affected by other health problems, including rabies, people should use precautions such as disposable gloves or an inverted plastic bag when handling bat carcasses. The public is also advised not to handle live bats that appear to be ill.
For more information on white-nose syndrome, visit the DOW website at: http://wildlife.state.co.us /Research/WildlifeHealth/WNS/
A photo of Colorado’s largest bat colony at the Orient Mine is available at:
http://dnr.state.co.us/ImageDBImages/23694.JPG