White-nose syndrome (WNS) is a new wildlife disease of unknown origin that has killed hundreds of thousands of bats across the northeast United States during the past three years and continues unchecked. It threatens to rapidly spread to the Midwest (including Illinois), home to many federally endangered bat species as well as some of the largest hibernating bat populations in the country.
The evidence collected to date indicates that human activity in caves and abandoned mines may be assisting the spread of WNS. The primary agent of concern is a fungus that is new to science and may possibly be an invasive species. This fungus grows best in the cold and wet conditions common to caves and abandoned mines and likely can be transported inadvertently from site-to-site on boots and gear of cave visitors. Therefore, the State of Illinois' Department of Natural Resources (Department), in conjunction with the U.S. Fish and Wildlife Service and the U.S. Forest Service, is taking steps to reduce the risks of further spread of WNS. This will involve the complete closure of all IDNR owned and/or managed caves within the State of Illinois for the foreseeable future. This closure formally took effect in early 2010. We hope that slowing the spread of WNS will buy time that is critical to confirming the cause of this disease and potentially implementing management actions to minimize the impacts to native bat populations. PLEASE NOTE that this closure includes ILLINOIS CAVERNS in southwestern Illinois.
We are not placing a time limit on this cave closure order – it will most likely last through all of 2011 and most likely through all or most of 2012. Scientists are working to determine the cause of WNS. We do not know when we will have answers to how WNS spreads. Whatever is causing WNS may remain in caves where bats hibernate even when bats are not present, and we are concerned that people may inadvertently carry WNS out of the cave with them. We intend to review this cave closure order on a quarterly basis.
We recognize that this complete cave closure effort will require sacrifice from the caving community and other citizens, and we regret this inconvenience. However, the observed devastation to bat populations, exceeding 90 percent mortality at many affected sites, and the evidence for human-assisted spread justifies that we exercise an abundance of caution in managing activities that impact caves and bats. These measures will not be a cure for WNS, but they are necessary to help slow the spread of this affliction and to reduce the risks to bat populations in North America.
Please note that the Department does not have the authority to close caves except on lands that we own and/or manage. We respectfully request that local units of government, public organizations, and private landowners throughout Illinois follow the Department's example and immediately close caves on their property and prohibit any human access in order to help prevent or slow down the spread of WNS. IDNR biologists can provide advice to private landowners regarding proper cave closure. Overall, the Department applauds the citizens of Illinois for their strong conservation ethic and long-time support of bat conservation. We appreciate your continued cooperation and assistance as we work together on the white–nose syndrome issue.
Questions regarding WNS and this cave closure effort should be directed to: Joseph Kath, Endangered Species Manager, Illinois Department of Natural Resources at 217-785-8764 or via e-mail at: Joe.Kath@illinois.gov