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.
WIldlife Biologist/Wind Energy Project Coordinator
Pennsylvania Game Commission