Blue Ridge Naturalist: Bats Endangered; The Crozet Tunnel Should Remain Closed


Bats Endangered; The Crozet Tunnel Should Remain Closed

© Marlene A. Condon

Many years ago, when I first heard that people were interested in opening the Crozet Tunnel on Afton Mountain to hikers, I e-mailed a Nelson County supervisor. I was concerned about bats that might be using the tunnel to hibernate or roost.

I’d hoped those flying mammals would be taken into consideration and would not be disturbed at all during hibernation and minimally bothered during the rest of the year.

With animal populations crashing all around us, I recognized the value of preserving healthy populations of whatever critters had managed thus far to survive the increasingly disruptive impact upon wildlife by humans.

The supervisor responded to me as if I were a naïve little girl. He assured me that there were plenty of bats around and that there was nothing to worry about. He ignored my pleas to avoid harming these animals.

But within just a few years of that correspondence, a disease called White-nose Syndrome (WNS) was discovered in a cave near Albany, New York. It gets its name from the white fungus that is often visible on the muzzles and bodies of infected bats.

The fungus is deadly, killing bats by weakening them when it invades their body tissue and disrupts their hibernation. According to the U.S. Fish and Wildlife Service, a minimum of 5.5 million bats have since died in four Canadian provinces and 19 states, including Virginia.

Many species of bats have been affected, including the Little Brown Bat (Myotis lucifugus) and the Tri-colored Bat, which was formerly known as the Eastern Pipistrelle (Perimyotis subflavis). The Little Brown used to be the most common bat in North America, but it’s now threatened with extinction.

Research has shown that populations of the Little Brown Bat and the Tri-colored Bat have declined by more than 90 percent. Both of these species have been found in the Crozet Tunnel by game biologists from the Virginia Department of Game and Inland Fisheries.

Our neighbor state to the north, Pennsylvania, has lost approximately 99 percent of its Little Brown, Tri-colored, and Northern Long-eared Bats (Myotis septentrionalis) since 2008, illustrating the speed with which almost entire populations of species can be wiped out. The probability for a rebound of populations is practically nonexistent.

Bats usually live for two to three decades and typically give birth to only one pup per year. Thus even if WNS could be stopped right now, it could take hundreds of years for populations to come back to pre-WNS levels. And that’s assuming there are no other assaults upon these mammals.

All organisms have important roles to play. The role of bats is to feed upon night-flying insects, limiting their numbers to sustainable levels. Bats themselves are fed upon by other animals, such as snakes and owls, and even humans in some parts of the world.

As species disappear, the environment comes ever closer to being unable to function properly. Mother Nature is no fool and has built into the system back-up creatures to fulfill roles played by other critters that may temporarily disappear or be in short supply.  But that back-up system is becoming more and more depleted, threatening the existence of our own species.

The cause of WNS is a European fungus that somehow found its way to the United States, perhaps upon the sole of a traveler’s shoe.  The spores from the fungus (Gomyces destructans) have been discovered now in 21 states.

If people pick up spores on their shoes or clothes and then go into caves or tunnels with roosting or hibernating bats, they can help to spread this infectious disease that, as of now, no one knows how to cure. (Humans are not affected by White-nose Syndrome.)

I myself would love to walk through Claudius Crozet’s engineering marvel. But the Crozet Tunnel needs to remain closed to the public. WNS is such a devastating disease that the U. S. Fish and Wildlife Service suggests that people stay out of places where bats are known—or suspected—to hibernate (hibernacula) in all [emphasis mine] states.

Right now, this is a voluntary moratorium, but people must ask themselves whether it’s more important for folks to be able to visit this site than it is to help bats that have rapidly become endangered and may disappear in our lifetime.

Some might argue that humans created this tunnel and therefore it’s theirs to do with as they wish. However, it’s virtually assured that the deadly fungus wiping out our bats was introduced to this country by humans and that they have helped to spread it. Thus it’s incumbent upon us to try to limit further harm.

Many environmental problems have been caused by human ignorance and carelessness. But in this case, Nelson County officials can’t feign ignorance. If they choose to open the tunnel, they are knowingly inflicting harm and demonstrating mankind’s continuing disdain for the natural world that sustains us.

Man can do extraordinary things; the Crozet Tunnel is proof of that. Unfortunately, man’s extraordinary conceit often causes him to believe that other life forms aren’t important. But they are. We do not live in a vacuum. Opening the tunnel now is clearly not environmentally prudent.

Marlene Condon will speak on “The Nature-friendly Garden” Saturday, April 6 at 10 a.m. at The Lodge at Old Trail, hosted by the Old Trail Community Garden.