Bats still threatened by mysterious ailment
White-nose syndrome, the mysterious affliction killing tens of thousands of bats, is heading south. First discovered in New York caves during the 2006-07 winter and then in New England, the ailment has spread across Pennsylvania, New Jersey and West Virginia.
Here’s a recent public radio report with good links for more information
After the break, read a summary put out this week by Bat Conservation International.
White-nose Syndrome: The Threat to Bats Grows
Four winters after its discovery near Albany, New York, White-nose Syndrome – a still-mysterious but deadly threat to American bats – has spread across New Jersey and Pennsylvania and into West Virginia. Preliminary reports, still unconfirmed by laboratory tests, suggest WNS may also be affecting hibernating bats in New Hampshire and Virginia. It has been killing bats, up to 90 percent of some infected populations – in New York, Vermont, Massachusetts and Connecticut.
West Virginia reports WNS at multiple caves and the Virginia Department of Game and Inland Fisheries reports finding bats with apparent WNS symptoms in at least one Virginia cave. If these cases are confirmed, Bat Conservation International (BCI) Founder Merlin Tuttle worries, “America’s most important remaining hibernation caves for Indiana bats and gray bats, both endangered species, could be seriously threatened within two years or less. Failure to find a solution could prove devastating.”
Tuttle, who is BCI’s executive director, has been studying the gray bat since 1959, when he was a high school student in Tennessee. That work expanded into his Ph.D. research at the University of Kansas. Tuttle’s continuing research and conservation work with the species led to its listing as an endangered species in 1976. After founding BCI 27 years ago, he and his team worked tirelessly to protect the species until now he feels “the gray bat’s populations are secure enough that it’s almost ready to be delisted. Or at least it was until WNS came along.” No evidence suggests gray bats are affected by WNS yet, but Virginia is on the northern edge of their range and roosts with hundreds of thousands of these bats are within easy reach.
Indiana bats, for which a formal recovery plan has been under way for several years, are among bat species that are being killed by WNS in the northeastern United States.
Bats are primary predators of night-flying insects, including many that are costly pests of crops and forests. The loss of bats could have serious ecological consequences.
White-nose Syndrome has killed hundreds of thousands of hibernating bats in the northeastern United States. Scientists do not know the cause, although researchers are trying desperately to solve this lethal puzzle.
A white fungus is found on the faces of many affected bats, and almost all are emaciated. The fungus has been identified, but it remains unclear whether it is a cause of the ailment or one of its symptoms.
Alan Hicks of the New York Department of Environmental Conservation, whose team originally discovered the syndrome, said the way WNS is spreading strongly suggests a disease-causing organism of some kind, possibly the fungus. He said that “transmission tests” are being conducted at the USGS National Wildlife Health Center in Wisconsin that should answer that question, “provided they are able to sufficiently match conditions in these caves. We expect those results in the next month or so.”
Bat Conservation International has been raising funds since last April to support tightly targeted research into causes and potential solutions to White-nose Syndrome. The nonprofit has provided nearly $100,000 to support a scientific conference on WNS research priorities and to fund grants for critical research, including the fungus study at the USGS Wildlife Health Center.
WNS was first seen in a single New York cave in the winter of 2005-06 and was found in four additional nearby sites the following winter. By 2007-08, it had spread throughout the state and into Vermont, Massachusetts and Connecticut. Now it has spread much farther.
Mick Valent, principal zoologist for the New Jersey Division of Fish and Wildlife, reports at least hundreds of confirmed bat deaths at three abandoned mines located a few miles apart in eastern New Jersey. (As natural habitat is lost around the country, bats frequently turn to old mines as sanctuaries of last resort.) Among the New Jersey mines is the state’s largest hibernation site – Hibernia Mine, where BCI helped build a bat-friendly gate in 1994. Some 30,000 bats, mostly little brown myotis but also some Indiana bats, now hibernate there.
“We’re seeing all the things that seem to define WNS: some bats with the white fungus on their muzzles, bats leaving the mine that are emaciated and dehydrated, bats flying out during daylight [in the midst of their hibernation season]. We are also seeing clusters of bats very near the entrance, the coldest part of the mine where ice is forming; we normally don’t see them there.” Dead bats from the mine tested positive for the fungus that’s associated with WNS, he said.
No bat kills were confirmed in Pennsylvania, but the state Game Commission notes that biologists DeeAnn Reeder of Bucknell University and Greg Turner of the commission found bats with fungus-covered faces in an old iron mine in Mifflin County. When they netted bats at the site last summer, they found no obvious problems, although some bats had white spots on their wings. “What the white spots represent is still unclear,” Turner said, but researchers believed they may have been early signs of WNS.”
In mid-December, the hibernating bats at the mine revealed no problems. But on December 20, some bats showed the fungus and a few had moved closer to the mine entrance, an abnormal shift during hibernation and a “red flag” for the biologists. By January 5, about 45 percent of the hibernating population had relocated toward the entrance. Something obviously is going astray at the mine, but exactly what that might be is not yet clear.
One of the top WNS researchers, Tom Kunz of Boston University, said he was not surprised the syndrome has expanded, but added: “We really don’t know what is causing the spread at this point.” He said researchers are sampling caves and mines across a broad area to determine whether the fungus can be present without the dire symptoms of WNS. “If it’s everywhere (across the landscape), that would suggest that the fungus is not what’s spreading, but that something else is” responsible for the spread of WNS and its bat fatalities into new regions. That answer must be found.