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John Chenger
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Release #007-09
Jan. 22, 2009
For Information Contact:
Jerry Feaser
717-705-6541
PGCNews@state.pa.us
NOTE: For a series of four photos to accompany this news release, please
visit the Game Commission’s website (www.pgc.state.pa.us), click on “News
Releases” and choose “Release #007-09.”
WHITE-NOSE SYNDROME SURFACES IN PENNSYLVANIA
By Joe Kosack
Wildlife Conservation Education Specialist
Pennsylvania Game Commission
SHINDLE, Mifflin County – Aware since 2008 that White-Nose Syndrome
appeared to be making its way to the Keystone State, the Pennsylvania Game
Commission now has evidence that the deadly bat disorder is likely present
in a mine near this small community in the state’s heartland. Where else
this may be occurring and the consequence to bats –a fragile guild of
wildlife species – remains an unfolding story.
In late December, DeeAnn Reeder, a biologist with Bucknell University, and
Greg Turner, a biologist with the Game Commission’s Wildlife Diversity
Section, found bats in an old Mifflin County iron mine that exhibited some
of the signs of White-Nose Syndrome (WNS), during field investigations into
bat hibernation patterns that included weekly monitoring for the disorder’s
presence in several Pennsylvania hibernacula. During this work, which had
been ongoing for weeks, dozens of bats suddenly had a fungus appear around
their muzzles and on the wing membranes, while many more displayed other
symptoms associated with this disorder. Several bats were submitted to the
National Wildlife Health Center in Madison, Wisconsin, which now is
reporting that the bats have preliminarily tested positive for the
cold-loving fungi found on many bats with WNS.
“Our agency, with assistance from the U.S. Fish and Wildlife Service and
other management partners, will work diligently and methodically to measure
the extent of the problem in Pennsylvania and monitor the disorder’s
progression,” said Carl G. Roe, Game Commission executive director. “This
find is a direct result of the Game Commission’s ongoing initiative to
proactively monitor for WNS.
“To date, no dead bats have been found in Pennsylvania. That’s a plus, but
it comes with no promise of what will or won’t follow. In New York and New
England, the disorder seems to arouse bats from hibernation prematurely.
Once they depart from caves and mines, they quickly sap their energy
reserves and die on the landscape. Mortality in some colonies has exceeded
90 percent, ensuring that any local recovery will be quite lengthy given
the low reproductive rate of bats. Little brown and the
federally-endangered Indiana bats produce only one young per year.”
Currently, researchers still are unsure exactly how bats contract WNS and
how it initially and, ultimately, affects a bat’s body. They cannot confirm
whether the fungus appearing on some bats is a cause or a symptom of the
disorder. What is clear is that the geographic area where WNS has been
documented is expanding. It was first found in bat colonies in New York in
2006, and subsequently in populations in Connecticut, Massachusetts and
Vermont in 2007. Now bats in Pennsylvania and New Jersey appear to be
affected.
“We do know that the visible fungus appears on some – but not all – bats
afflicted with WNS, and that a significant percentage of bats in affected
hibernacula move closer to the entrance,” explained Turner. “The bats
eventually leave their hibernacula – often in daylight, which is unnatural.
Most of those bats likely die on the landscape, but some may return to the
cave or mine they left. Researchers cannot determine what bats are
searching for, or if they’re hunting for anything. Most bats found dead on
the landscape have depleted their fat reserves.”
About the only thing certain about WNS is that its ambiguity continues to
baffle the cadre of researchers who are working long hours to positively
identify what it is, and if there is anything wildlife managers can do to
disable it. WNS does appear to be spreading bat-to-bat, but it’s unknown
whether it’s passed in summer roosts, or hibernacula, or both. It also is
unknown yet whether the cause of WNS will linger in hibernacula without
bats.
“Of course, there’s also the possibility that bats have been – or are being
– poisoned somehow,” Turner said. “The source could vary; insecticides,
herbicides, livestock supplements, changes in the composition of building
materials, even changes in air and water quality. That’s what makes this
whole search so open-ended. But, to date, the disorder is found only in
America’s Northeast, so it would appear the source is here, too. That’s a
solid lead, if it is something like a toxin.”
New York and New England have lost tens –maybe even hundreds – of thousands
of bats to WNS over the past two years. Significant losses to bat
populations could have ecological consequences because of the role that
bats play in the environment. Across Pennsylvania, bats eat tractor-trailer
loads of insects on summer nights, making our backyards more bearable and
crop yields more bountiful.
“Bats have survived for more than 50 million years because they are tough
mammals,” said Lisa Williams, a Game Commission wildlife diversity
biologist. “But they have become increasingly vulnerable. Destruction and
disturbance of caves, changes to summer habitat, all have impacted bat
populations. White-Nose now presents more uncertainty for bats. Quite
frankly, we’re not sure yet that we can help them survive this threat.
We’re looking for answers. “An impressive team of researchers is in place.
But this whole situation has been so sudden, so fluid and so devastating to
bats, that it makes it incredibly hard for wildlife managers to develop a
conservation response.”
The Game Commission spent last summer monitoring the state’s bat maternity
colonies for signs of mortality, both in adults and juveniles. Bats also
were mist-netted and checked for abnormalities. Both efforts shed light
into Pennsylvania’s unfolding situation, but neither provided conclusive
evidence as to what’s happening.
“We came out of summer knowing that we hadn’t lost major numbers of bats,
but we did notice that some bats had small white spots on wing membranes,”
Turner said. “What the white spots represent is still unclear, but some
researchers believe they may be the early signs of WNS.
“This past fall we began to examine the health of our bats to see if they
came into their winter quarters prepared for hibernation. We also are using
telemetry gear and data-loggers to monitor the body temperatures and
arousal patterns of hibernating bats, hoping to shed light on how the
emergence of WNS may be affecting individuals, hibernating clusters and the
wintering colony.”
Weekly battery changes are needed to keep the telemetry receivers (data
recorders) going. It was during one of these battery changes that Reeder
and Turner noticed changes occurring in the Mifflin County hibernating
colony. As recently as Dec. 12, there was no change to bats in the mine.
Then on Dec. 20, they noticed bats starting to shift toward the mine’s
entrance and a small amount of fungus on some of them. Bats normally don’t
hibernate at entrances, so this movement was interpreted as a red flag. On
Dec. 29, about 150 of the 2,200 bats in the mine appeared to be affected.
By Jan. 5, about 45 percent of the mine’s wintering colony had relocated
toward the mine’s gated entrance.
Reeder and Turner are monitoring three sites in Pennsylvania to record the
arousal patterns and body temperatures of hibernating bats. This work, part
of a multistate effort funded primarily by the U.S. Fish and Wildlife
Service, also is being conducted in New York, Vermont, Michigan and
Kentucky.
“This research may tell us if bats are arousing too frequently and
consequently burning off fat reserves prematurely, or if they’re not
lowering their body temperature enough to support hibernation,” Reeder
explained. “It may also show that bats are having difficulty going back
into hibernation after being aroused.”
The Game Commission will be surveying 20 to 30 hibernacula between January
and March as part of annual fieldwork and during those visits will be
monitoring for signs of WNS. The agency may add more sites to the scheduled
list of caves and mines to ensure good coverage across the state. The
agency also will assist researchers who are doing fieldwork instate. This
work includes investigating metabolic rate of hibernating bats; studying
the immune response capabilities of bats; and measuring whether bats have
sufficient amounts and types of fat heading into hibernation.
“This winter and early spring, the Game Commission is asking the public to
keep an eye on Pennsylvania’s bats,” Roe said. “It is unusual to see bats
flying outside or around your home in January, February and March. If you
see winter-flying bats, if you find multiple dead bats or if you or
neighbors repeatedly find dead bats in a particular area, please report the
incidents to the nearest Game Commission region office.”
For Region Office contact information, as well as a listing of counties
each serves, please visit the agency’s website (www.pgc.state.pa.us), and
click on “Contact Us” in the left-hand column and scroll down to the region
listings.
For more information on bats, visit the Game Commission's website
(www.pgc.state.pa.us), select "Wildlife" and then click on the photo of the
bat. To learn more about WNS, visit the USFWS's website at
www.fws.gov/northeast/white_nose.
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