NEBRASKAland Magazine is dedicated to outstanding photography and informative writing with an engaging mix of articles and photos highlighting Nebraska’s outdoor activities, parklands, wildlife, history and people.
Issue link: http://mag.outdoornebraska.gov/i/708333
AUGUST-SEPTEMBER 2016 • NEBRASKAland 59 the fungus from cave to cave and state to state in their day-to-day or seasonal movements. The disease has been found to affect seven species of hibernating bats, including four found in Nebraska: the northern long-eared, little brown, big brown and tricolored bats. The fungus that causes it has been found on five other species, two of which, the silver- haired and eastern red bat, are found here. The symptoms are not always visible, and not all infected individuals perish. Monitoring has shown some cases of bats surviving infection, and population declines have slowed or stopped in some locations, giving researchers hope that bats had or are developing a resistance to the fungus. Some species, like the big brown bat, are more resistant to the disease than others. And while the northern long- eared bat may be among the most susceptible, the disease has placed the Indiana and gray bats, which both were listed as endangered prior to the arrival of white-nose syndrome, at risk of extinction. No deaths or outward symptoms of the disease have been found in Nebraska, where the only positive sample came from an abandoned, century-old, underground gravel mine in Cass County. But researchers have only tested for it in four locations. As of yet, they have not been able to obtain access to huge underground limestone mines in Cass County which historically held large populations of roosting and hibernating bats. Researchers are looking for ways to fight the fungus. The logistics of deploying any panacea that may be found to all hibernacula makes winning that fight unlikely, and most researchers expect it to continue its westward march and eventually spread throughout North America. Wind Power Another major threat to bats rose from the horizon before white-nose syndrome arrived, but has increased greatly since 2006: wind energy. The generating capacity in the United States has risen nearly six-fold since then to more than 61,000 megawatts, and there are now about 49,000 wind turbines operating in 40 states, including 890 in Nebraska. While wind energy has reduced the country's dependence on fossil fuel, there has been an environmental cost. The rotating blades of the turbines, some 130-feet long, can reach speeds of 179 mph and have been found to kill passing birds and bats. A recent study estimated between 140,000 and 328,000 birds are killed annually. Another study estimated 600,000 bats die each year, a conservative number that only looked at deaths during migratory periods. In both cases, the estimates were based on ground surveys beneath the turbines. Most bats are killed when they are struck by rotating turbine blades, but a few die from by the respiratory trauma caused by the sudden drop in air pressure around the blades. The highest rates of bat mortality have been recorded at wind farms in the Appalachian Mountains in Tennessee and West Virginia, where bat populations are high. Surveys at wind farms in Nebraska turned up comparably fewer bats, but most are located in open grasslands where there are far fewer of the winged mammals. The migratory hoary bat is killed by wind turbines more than any other species. Researchers speculate they may be attracted to insects that are found near the turbines, that they confuse the towers as trees and attempt to roost there, or that some other feeding or mating behavior is involved. In many cases, companies have been willing to work with regulatory agencies to monitor bat and bird mortality with pre- and post- construction surveys, including in Nebraska, where most voluntarily complied with requests by the Game and Parks Commission to do such monitoring, which is ongoing. Researchers looking for ways to reduce bat mortality are finding possible solutions. Studies have shown that rotating the blades of the turbines so University of Nebraska at Kearney student Cody Dreier swabs a tricolored bat for white-nose syndrome. The bat and others were collected as they hibernated in Happy Jack Chalk Mine near Scotia and returned there after testing. Condensation covers the fur of a tricolored bat hibernating in Happy Jack Chalk Mine near Scotia.