Nearly 30 people attended a special presentation given by Greg Turner of the Pennsylvania Game Commission and Aura Stauffer of the Department of Conservation and Natural Resources on Thursday, April 30, at the Winnie Palmer Nature Reserve at Saint Vincent College, Latrobe. Kim Metzgar of the Mid-Atlantic Karst Conservancy arranged the presentation.
Among those attending were MAKC board members John Long, chairman; Mike Schirato; Mike Kern; Andrea Gillis and Carl Pierce, secretary. Other cavers spotted in the crowd included Tom and Kim Metzgar, Caleb Hammond, Mike Wolf, Johnny Motto, Jeff Dunn, Dennis Melko, Katie Schmid and her husband, Aron, Stephanie Wolf and Lisa Hall, director of cave studies at Laurel Caverns.
Turner and Stauffer provided a valuable update, and stayed for nearly three hours to inform those attending about the latest research and the spread of White Nose Syndrome in Pennsylvania.
Turner started out by noting that a syndrome is a suite of symptoms, and that it won’t become a disease until after researchers discover what is causing it.
First discovered in Albany, New York, during the 2006-2007 hibernation season, in four sites, the mortality rate was 90 percent in Hailes Cave, 97 percent in Schoharie Caverns, 91 percent in Gage Caverns and 87 percent in Howe Caverns, which has Indiana bats. In 2007, the mortality rate in Barytes Cave was 100 percent.
Turner explained that the Pennsylvania Game Commission counts bats every two years, identifying by species and count. Bats, he said, are creatures of habit. They return to the same caves every year for hibernation. Some have been known to roost on the same spot for as long as twenty years.
Currently, what is known is that a fungus grows on affected bats on exposed skin and muzzles, and the bats have unresponsive behavior, shift the locations of their roosts, emerge from hibernation more frequently, fly during daytime when they normally do not fly, and become emaciated and die. Bats typically leave their roosts in mid-April and those affected by the syndrome leave in December or January.
Turner and Dee Ann Reeder of Bucknell University, with Stauffer assisting with caves on State Forest Land, have been conducting research with mini data loggers glued to the backs of bats. This research has been done in Barton Cave in Fayette County as well as Shindle Iron Mine in Mifflin, and a clay mine in Fayette County. Shindle became one of Pennsylvania’s ten confirmed sites.
There was a fungus confirmed in Barton Cave; however, after testing it was determined NOT to be White Nose Syndrome and the site still remains free of WNS.
The fungus has spread very quickly, from New York to Vermont to Massachusetts to Connecticut. In fact, it spread to all 28 known hibernacula within 130 kilometers of the initial site and five of the 19 sites between 130 and 170 kilometers. Sites with White Nose Syndrome have greater than 80 percent mortality and well over a half-million bats have died thus far.
Turner noted that there is no evidence thus far discovered indicating internal or systemic malfunction. Ninety percent of fungi do not cause mortality. They usually take advantage of something that is weakened, he added. However, this one does attack live cells and remains the leading candidate. There are those, he said, who thought the syndrome was a bacteria as well. But currently there is not much known about the syndrome.
The fungus has been confirmed at ten sites in Pennsylvania. Six are caves (five gated)…three coal mines (two gated) and one gated iron mine. The caves in which it has appeared are gated as well (except Alexander Caverns…..in which the water entrance is technically open. Counties in the state in which White Nose Syndrome has been verified are Mifflin, Centre, Lackawanna and Luzerne. Due to the fact that no causative agent has been identified, in fear of spreading WNS themselves, or adding additional stress to bats that appear to dying from lack of fat reserves, Turner said general bat surveys have been halted unless it contributes to more than just counts of bats. For sites where they are conducting WNS research, they purchased and dedicated new gear to each particular site so there was no potential for cross-contamination.
The Game Commission conducts winter bat surveys in 30 to 35 sites each year, Turner explained. No site is counted two years in a row, he said, as a means to keep the bats as healthy as possible. The reason is because each added disturbance during hibernation will reduce the bats’ supply of energy to complete hibernation, spring migration, and the successful production of offspring. The less energy the bat has leaving hibernation will increase the time it takes for the bat to complete its migration, increase the number of days until the pup can be born, and thus give the young of the year less time to learn to fly and put on an adequate supply of fat to survive their first year of hibernation..
This winter, the PGC started its surveys early and in January researchers became nervous about human transmission of the fungus. “So, we weighed the costs and benefits about collecting data and decided it was not worth the risk to tens of thousands of bats,” Turner said. Thus, as a result of the spread of WNS to the state, winter bat surveys were put on hold.
In northeast Pennsylvania there are thousands of coal mines, and many that appear to have bats and be impacted, Turner said, and “we don’t even know where many of these mines are. In the coal mines there are multiple seams of coal. Some can have dozens of small entrances about the size of a grapefruit. We don’t even know where all of these entrances are.”
Turner also noted that the PGC set up a hotline and web link where people can report a sick bat. Calls have been reported in 19 counties. There were 30 or 40 reports of bats flying when they should have been hibernating.
Turner said that Alexander Caverns in Mifflin County was visited on October 13, 2007, by people who had been caving in affected New York sites before any decontamination protocols were in affect. Researchers know this because they began tracking sites, asking cavers where they had been. “There was a long list, with many states included.” As it turned out, there were 15 dead bats in Alexander Caverns in the spring of 2008 after the hibernation period had ended and by the winter of 2009 barely any bats returned to the cave. The bat survey in 2009 measured an 87 percent mortality, from 1800 bats to between 125 and 130 bats.
The cave became a point source of spread for the central part of the state, with caves and mines within an eight-mile radius being confirmed, and in late March/early April being found out to about 15 miles of each other, including Sharer Cave and Shindle Iron Mine. Sharer, which is gated, was clean, but then two bats developed White Nose Syndrome. Researchers believe the infected bats might have traveled from one infected site to Sharer, and possibly spread it from site to site.
All six hibernating bat species have been impacted and it has spread 15 to 20 miles in a single winter, he said. Shindle Iron Mine was clean on December 3, but by December 20 there were the first signs of a fungus. By December 29 samples were collected and up to 40 percent of the more than 2000 bats had shifted their roosts. By January 25 there was a decline of 457 bats and 45 percent of the bats had the fungus. By the end of March there was a 95 percent reduction and only 126 bats remained. In October of 2009, Turner reports that only six bats returned to the site, a greater than 99 percent reduction in a single year.
Turner and Reeder were putting little back packs on the bats to study when they are flying and 95 percent were gone from the site and the juveniles had the fungus. At one entrance count there were 100 dead bats in one week, he said.
The incubation period appears to be less than six months and juveniles born in June are dying in December.
Researchers are currently looking at potential causes of bat deaths. Theories include a) the bats are starving due to a change in body condition caused by inadequate deposits of body fat stored prior to hibernation, b) premature depletion of fat, or c) a water imbalance. Researchers include Reeder; Craig Frank, Fordham University; Eric Brotzke, U.S. Amy Corps of Engineers; ERDC Environmental Lab, Turner and many others.
Normally, Tuner said, a bat can wake up six to ten times a winter if it gets up once a week. In order to wake up a bat’s body temperature must rise from 40 degrees to 102 degrees, and it takes a tremendous amount of energy to heat up. Bats with White Nose Syndrome wake up more frequently and stay up longer.
Turner and Reeder are using two methods to obtain arousal data on hibernating bats, using radio transmitters and little backpacks both designed to monitor skin temperature. “By monitoring their temperature, we can determine when, how often, and for how long a bat will arouse from hibernation,” Turner said. With the data logging “bat backpacks” “we are trying to set up data points to take information every 30 minutes. We know it takes about an hour. and a half to wake up. They start to wake up more frequently and if the wrong bats arouse too frequently, they die.”
The data is better with the backpack version, but if the bats fly away they will not be able to retrieve the data. With the small and light transmitters Turner and Reeder are attaching with glue, “as long as they are in sites and in reception distance from the antenna then we can get data from them,” he said.
Bat hibernation patterns in each site are different due to different temperature and humidity. The Barton Cave study is using the backpacks. Researchers glue them on the backs of bats, then have to recover them. There are also some in Layton Fire Clay Mine, Fayette County.
Turner and Reeder constructed a circuit board and battery pack, making between 150 to 200 in a month. They can collect data for six months, or earlier if a bat dies. When a bat started getting up every three to four days or every day then it didn’t take long until it died. Personnel netted the openings off so the bats did not fly away to die on the landscape, and so they didn’t lose the data.
The torpor bouts were very short from 1.5 to 2.5 whereas normal is 13 to 17 days.
With the Shindle Iron Mine, the control site for the study, bats were getting up every four days in the first year of White Nose Syndrome. One bat was up for six days.
Turner said the next step is to review all of the data for 2008-2009, and continue to monitor the hibernacula. A one-year caving moratorium should help keep the spread of WNS to just sites around the already affected sites. He also may be experimenting with a fungicidal treatment. Surviving bats and maternity colonies will be studied, as will the immune system competence between bats with White Nose Syndrome and healthy bats, and microclimate studies of hibernacula. Game Commission personnel will also be doing educational outreach. Researchers hope to publish some results starting in 2009.
Researchers are also working to see if they could find a substance that would prohibit the growth of the fungus. Bread has a mold inhibitor in it, he pointed out, so possibly there is something that could prevent the fungal growth. The trick is obviously not making the situation worse by destroying the delicate cave ecosystem or its inhabitants. Any treatment that may be attempted will be restricted to mines.
If any potential compounds come to light, one vehicle to treat bats Turner is looking at developing is a misting system that could potentially spray bats exiting or entering a cave. This kind of system would work well in a narrow entrance and may work well in the fall when bats are swarming. Anything will be considered, he said, if it can help bats survive another winter and allow researchers more time to work.
“This mortality is unlike anything we have ever seen with bats,” Turner said, at between 95 and 98 percent in New York sites. “In Pennsylvania we hope to have more data next year, and maybe that will make a difference. There might even be a difference the further south we go, so maybe we can help the bats. We’re just hoping for survivors, for a next generation.”
He also questioned whether or not the fungus could survive the summer, noting he and others will be following bats to see where they are migrating to, and to see whether reproduction is down, if they are reproducing, or not reproducing at all. A bat can live 30 to 40 years in the wild, but females produce only one pup a year. With a slow reproductive rate, and high mortality, White Nose Syndrome is “devastating ecologically,” Turner said. He also noted that “we want to see if it is transmitted in the summer, if bats spread it to other bats.”
Researchers are looking at whether or not pesticides weaken a bat’s immune system, whether or not heat will kill the fungus (the microclimate study), and whether or not humidity relates to survivorship, as well as whether or not there is something that helps build resistance in bats. They are doing soil sample collection, studies of metabolic rates, and body fat studies, as well as a pathological investigation into the disease.
“There is no smoking gun right now,” he said. Turner and Stauffer have assisted with all studies in Pennsylvania, something he said is very time and labor intensive. They note that cavers can do some things, such as report sick bats and follow strict decontamination protocols when the moratorium is no longer in place. MAKC will announce major initiatives on its website. However, we note that since the news evolves almost daily, the best source of information (which we have linked to) is the White Nose Syndrome site maintained by the NSS, as well as other websites.
By Kim Metzgar