While
visiting my parents this past weekend my dad reminded me about my interest in
wildlife. He recalled an incident from
about 25 years ago when my older brother and I captured a “dead” bat in the
barn with one of our butterfly nets. We
were so excited we took it inside the house to show him. We found dad napping and notified him of our
catch. He sleepily told us not to bring
butterflies into the house and I excitedly informed him that it wasn’t a
butterfly—it was a bat! Well, Dad kind
of shrieked which woke up the “dead” bat, which started flapping in the
net. The bat flapping in the net scared
my brother who promptly dropped the net onto Dad’s chest. Dad flipped off the couch, ran out the door,
and somehow flung the bat out of the net like a slingshot. My brother and I spent the next two hours
learning about what was and was not appropriate to play with or bring in the
house.
As
we were reminiscing about the bat adventures of our old farmhouse he stated
that it was not as funny as I make it sound.
He smiled and pointed to my two young boys who were drawing on my car
with sidewalk chalk and then broke into laughter as I tried to explain to my
kids what they can and cannot draw on. Afterwards,
he just smiled to me and said he cannot wait to hear about what my kids bring
into my house.
I
thought about this statement during the drive home on Sunday night. I currently live in an old farmhouse, similar
to the one I lived in when I was a kid.
I know it has some bats in the attic, and there were definitely some in
the barn and outbuildings because I swept out the guano. But in five years when my kids are out
exploring the farm like I used to, will there be bats in those buildings for
them to discover?
In
Pennsylvania, bat species are encountering several direct threats. White nosed syndrome has devastated
residential hibernating bats in Pennsylvania.
White nosed syndrome was first documented in New York during the winter
of 2006-2007 and has now been documented in 19 states and four Canadian
provinces. It was first detected in
Pennsylvania in 2008. Hibernacula
surveys by the Pennsylvania Game Commission revealed a 98 to 99 percent decline
in little brown, tri-colored, and Northern long-eared bats. Before white nosed syndrome, little brown
bats were one of the most commonly observed bats in Pennsylvania.
Wind
energy development is another threat to bat species. Unlike many other development projects such
as power lines or pipelines which have initial wildlife impacts, wind turbines
have large moving blades that can impact wildlife for the life of the
project. In 2007, the Pennsylvania Game
Commission created the Wind Energy Voluntary Cooperative Agreement. This is an agreement between the Game
Commission, which has jurisdiction over Pennsylvania birds and mammals, and
wind energy developers to study the effects of wind energy on wildlife and
develop ways to avoid, minimize, and mitigate for negative impacts. Data collected via the Voluntary Cooperative
Agreement shows an average mortality of 25 bats per turbine per year for wind
sites in Pennsylvania. There are
currently over 500 turbines in operation in Pennsylvania which means over
12,500 bats are killed by wind turbines in Pennsylvania each year. With more wind farms planned in Pennsylvania,
the yearly bat mortality will continue to increase unless some minimization
methods are implemented. Three quarters
of the bats killed in Pennsylvania are migratory tree bats such as the hoary,
eastern red, and silver-haired bats.
These bats migrate south through Pennsylvania in the fall and north through
Pennsylvania again in the spring. Meaning
that these bats essentially run a gauntlet of wind farms up and down through
Appalachia. Since bats are relatively
long lived and have low reproduction rates, generally one young per year,
mortality from wind farms could have serious implications on these migratory bat
populations.
There
are other threats that bats face. Bats
can be killed by automobiles driving on roadways. Bats can be killed by feral pets such as
cats. Bats can be killed by homeowners
when they inadvertently seal them in because people do not want bats in the
attic. There are also indirect threats
such as habitat loss and pesticide use.
Residential and industrial development threatens historical foraging and
roosting sites. Increased pesticide use
reduces potential prey for bats. So not
only is their original foraging area no longer suitable, but their food was
also removed. Recreational activities
such as caving can disturb bats while hibernating. Dumping trash into caves and mines can close
entrances used by bats, eliminating suitable hibernacula.
Bats
appear to be facing a stacked deck. Hopefully,
as a society, we can recognize the implications our actions have on wildlife,
and avoid and minimize these impacts for the benefit of all wildlife. While there are many threats to bats, we
should identify the major threats to bats, such as white nosed syndrome, and develop
ways to minimize the spread of this disease while protecting the species most
at risk. For direct threats such as wind
energy, we should identify ways to avoid potential impacts and minimize the existing
impacts through adjusting cut-in speeds, deterrents, or other methods. We should be aware of the various impacts on
bat species and avoid and minimize them to the greatest extent possible.
Maybe
this will allow my kids the great experience of watching their mother screaming
hysterically at the dinner table because a wayward bat emerged via the kitchen
instead of exiting the attic through the eaves.
John
Taucher
WIldlife Biologist/Wind Energy Project Coordinator
Pennsylvania Game Commission
