State bat scientists go underground this winter to search for a deadly bat disease.
Keeping Wisconsin bats healthy.
Starting this month, Jennifer Redell, Heather Kaarakka and Paul White will squeeze through critter-sized cave openings, belly crawl through pitch black tunnels, and paddle through water in mines in search of a deadly bat disease that's getting ever closer to Wisconsin.
Coming upon clusters of hibernating bats, they'll look for fuzzy white noses – a tell-tale sign of the disease, white-nose syndrome – photograph the bats, and leave the way they came. They and fellow staff of the Department of Natural Resources' Wisconsin Bat Program will repeat this routine most days through February and March, searching dozens of caves and mines in Wisconsin.
It's a mission not for the faint of heart nor for the claustrophobic – but one bat crew members take on because they know they are in a race to save Wisconsin bats. White-nose syndrome has killed 5.7 to 7.7 million bats in the past five years in the eastern United States and Canada. The fungus causing the disease was documented in 2012 within 30 miles of Wisconsin in a popular cave in northeastern Iowa. The disease has no known control nor cure though researchers are working furiously to find both.
"The disease is unprecedented and unbelievably devastating," says Redell, DNR's cave and mine specialist. "We are seeing the most precipitous decline in Northern American wildlife in recorded history."
High stakes at home and around the globe
"We stand to lose half of our bat species," says Paul White, a DNR conservation biologist. "And that is a horrific prospect, not just for bats, but for the health of some of our most sensitive ecosystems and for the agricultural and forest industries that depend on the free pest control that bats provide."
Bats are voracious insect eaters – a single female who is nursing can eat up to her body weight in insects every night – and help keep flying crop and forest pests and mosquitoes in check. A recent national study estimated the insect-eating services that bats provide are worth between $658 million to $1.5 billion alone for Wisconsin's agricultural industry.
Wisconsin has one of the highest concentrations of hibernating bats in the Midwest, with up to 300,000 bats – some from the neighboring states of Illinois, Indiana, Minnesota, Iowa and Michigan – spending their winters here. So any disease affecting Wisconsin's hibernacula has far reaching impacts on the summer landscape here but also regionally, and increasingly, globally.
"Wisconsin has three of the largest little brown bat hibernacula in the world because populations in the eastern United States have plummeted since the arrival of white-nose syndrome in 2006," White says.
The discovery in Iowa underscores that the fungus is still on the move, says Richard Geboy, Midwest regional white-nose syndrome coordinator for the U.S. Fish & Wildlife Service. And the fact that the fungus was detected prior to the onset of white-nose syndrome "should serve as a warning to all of us that the fungus could be anywhere and is still on the move to new locations."
The good news for Wisconsin, Geboy says, is the state is among the places where exciting research into the disease is occurring, and the state has taken "proactive" efforts to protect its bats. These efforts include categorizing the disease as an invasive species, a designation that allowed the state to act quickly to enact steps aimed at slowing the introduction of the disease here.
"Our first efforts must be to do everything within our capabilities to prevent it from arriving," Geboy says. "Fortunately, Wisconsin has very strong policies preventing the introduction via human transmission. Also, Wisconsin has been involved in the preparation of the National Plan for managing white-nose syndrome, and DNR employees have been active participants on a number of committees at the national level."
When being awakened early can be deadly
White-nose syndrome is named after the powdery white fuzz that can develop on hibernating bats' noses, ears and wings after infection with the fungus Geomyces destructans. Bats hibernating near cave entrances where it's colder or bats flying around outside at night are other signs of the disease.
The disease causes bats to awaken more often while they are hibernating, thus burning up the critical stores of fat they need to make it through winter. Bats can burn 30 to 60 days-worth of fat if they are woken up or disturbed.
The disease has been found to spread bat-to-bat and cave-to-bat. The fungus spores persist in the soil and on rock surfaces of bat hibernacula, which is why Wisconsin has strict decontamination measures for caving equipment and clothing to minimize the risks of unintentional human transmission. Since whitenose syndrome was detected in Albany, N.Y., in 2006, the disease has infected 19 states and four Canadian provinces.
DNR's bat crew, in addition to working regionally and nationally on the disease, has put in place a comprehensive effort to learn more about Wisconsin bats, to keep the disease from being introduced here, to slow its spread if it arrives, and to rebuild bat populations if the disease pushes colonies or species to extinction. The work is all the more impressive because they have done this on a shoe-string budget, patching together federal grants and funding.
They've built working relationships with landowners of mines and caves and have helped them take actions to keep the disease at bay, like limiting human access to cave sites and training people how to clean equipment and gear that have been in or near a cave or mine.
In June 2011, Wisconsin added another important layer of protection when it added four cave bat species to the state threatened species list. The new listing makes it illegal for people to kill, transport or possess bats without a valid permit. The Department of Natural Resources also has put in place administrative rules that give the department authority to manage bats and establish disease prevention and control options.
Citizens to the bat rescue
"Perhaps most importantly, the Wisconsin Bat Program reached out to volunteers for help, and to property owners whose barns, attics and caves are harboring bats, and enlisted them in the fight to save Wisconsin bats," Redell says.
Volunteers have helped the bat crew locate the bat houses, barns, attics and other sites where bats roost over the summer. They also use special hand-held ultrasound equipment and GPS technology to help "listen" for bats and record their numbers and locations.
Since 2010, more than 400 people have told the Department of Natural Resources of roosts on their property, or roosts they know of, adding more than 100 new monitored sites to the existing bat roost database, Kaarakka says.
In addition, more than 1,000 people have gotten acoustic survey training and used the equipment to help detect bats. "In addition to gathering baseline data about bats in Wisconsin, summer roost monitoring is important because the availability of summer roosting habitat limits populations of bats," Kaarakka says.
Other outreach efforts have included sponsoring a bat festival in May in Madison that has drawn hundreds of people to get a close up look at bats, build bat houses, and learn more about the world's only truly flying mammal.
"We've tried to do a lot of education and outreach in the last two years," Redell says.
With so many roosts to monitor and few staff to conduct counts, volunteers are crucial to gathering the needed data to help understand Wisconsin's bat populations, and their habitats and habits. Soberingly, their information will be critical for helping the state proceed with recovery plans should whitenose syndrome arrive and lead to the collapse of Wisconsin cave bat colonies.
On the leading edge of WNS and research
The Department of Natural Resources has been closely involved with researchers and other state biologists throughout North America in order to maintain and incorporate the most current knowledge of the disease and update the state's response plan. The National Wildlife Health Center in Madison and the University of Wisconsin-Madison have played big research roles as well; the health center, in fact, determined Geomyces destructans as the cause of white-nose syndrome.
Data collected by DNR's bat crew and volunteers over the last few years is starting to pay dividends in the lab and on the ground. The bat crew's survey of 120 sites last year for signs of white-nose syndrome yielded a clean bill of health for the bats and also information including the number of bats in a hibernaculum, temperature and humidity and other conditions within that hibernaculum.
UW-Madison wildlife ecology researchers are plugging that data into computer models to help predict how and which Wisconsin hibernacula will be reached by the disease, depending on whether the fungus advances from the north, from Canada, or from the south, from places like Iowa.
That information, along with our baseline data, will help us determine where to focus our disease management, and conservation and recovery efforts, Redell says.
The Department of Natural Resources is partnering with the USGS National Wildlife Health Center and other states in research to help determine temperature and humidity conditions in underground bat hibernacula that allow the fungus to thrive. The information will help the Department of Natural Resources assess which hibernacula may support development of white-nose syndrome in hibernating bats and whether manipulating conditions within certain hibernacula may work to keep the disease at bay, or reduce the number of bat deaths, Redell says.
The Department of Natural Resources also is partnering with the University of California-Santa Cruz and other states to better understand how and when the fungus spreads and how it affects different bat species. Such results will help the department understand the impact on bats in Wisconsin and the risk of local extinction or extirpation as well as how effective certain management actions are, including closing caves and treating bats, Redell says.
And bat crew members, in research with the federal wildlife agency, an environmental consultant and other states, will be placing metal bands on the wings of bats to allow for easier tracking over time and to assess how such handling affects the bats. Collectively, such information will help DNR staff track bats that survive white-nose syndrome, and also understand how stressful being handled during hibernation is for the bats.
Next steps if WNS is found
The Department of Natural Resources' exhaustive survey in 2010 of 120 possible hibernacula for signs of white-nose syndrome turned up nothing, as did last year's search of 120 sites where bats were most likely to be found.
If white-nose syndrome is found, DNR staff and the landowner will work together to implement a management strategy specific to the site and based on a variety of factors. Management options vary and include decontamination, cave and mine access management, rehabilitation of sick bats and disease treatment, Redell says.
"If we find it, we have an implementation strategy to guide us," she says. "A science advisory committee as well as stakeholders will look at the different variables before making recommendations. We may respond differently if it shows up at an isolated site in northern Wisconsin, or a tourist cave with only 20 bats. We've developed a suite of potential management and control options but won't know exactly what we're going to do until we know what we're facing."
Bat crew members have been expecting to find the disease every year since 2009.
"We go in every year hoping for the best but prepared for the worst. Every year we don't find it allows time for more research to help get ahead of the disease," Redell says.
Lisa Gaumnitz is a public affairs manager for the Wisconsin Department of Natural Resources.