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Bats in the Spotlight

bats_1BY Will Stahl

Bats and I go back a ways. The first one I ever saw washed up dead on the shore of the lake I lived on. No more than ten, I saw at once what it must be with its matted, furry body and translucent wings. It was creepy and fascinating all at once.

In later years I had bats flutter up in my face as I ripped the wood shingles off a 130 year-old house, squeaking as they flew frantically to holes they obviously knew of.

I killed one with a broom because I could not figure out how to get it out of my house and trapped another between a record album and a toy pail for live release.

When my kids were growing up in Peoria, we sat with the neighbors watching them loop and whirl in the twilight, eating insects that would have otherwise annoyed us.

Though 25% of all mammal species are bats, they exist in the twilight edges of our consciousness. Because they are all nocturnal, we do not see the role they fill in our natural world and we so rarely see one close. When we do, it carries the load of our subconscious impressions. Bats have become associated with all the Halloween imagery of witches, vampires, and evil in general. Flying is a natural characteristic of birds––in mammals it is strange and suspect, especially when they only do it at night.

By the twenty-first century, most educated people, whatever their subconscious dread, understand that bats are significant in controlling insect populations, and their absence would allow our tiny tormentors to multiply unchecked. It is then with alarm that the news has spread that a hitherto unknown disease has been killing bats in huge numbers.

bats_3In recent years we have heard about the die-offs of amphibians and honeybees, monarch butterflies, songbirds and northern moose, and this may seem like just one more. In those cases causes are mostly uncertain and diffuse. Scientists know what has been killing the bats.

“White nose syndrome” is caused by Pseudogymnoascus destructans, a cold-loving fungus that thrives in caves. It appears as a white growth on bats’ faces and wings. It was first reported in 2007 but was later identified in a photo from 2006 taken in New York State.

Since then it has been found in 25 states in the eastern US and five provinces of Canada. It was unknown on this continent before 2006, though it is present in healthy bats in Europe.

Scientists believe humans must have introduced it, as it was first identified in a New York cave near where commercial caves draw thousands of visitors a year. Studies have shown that the fungus is not spread by airborne transmission, but it can persist in soil and clothing for a long time.

This evidence that the fungus could be spread by human activity has prompted the US Fish and Wildlife Service (USFWS) to encourage decontamination of clothing and equipment by cavers and close some caves to human visitation completely.

For a time scientists believed it caused bats to die because it aroused them from their usual winter torpor so they’d fly around. Without food available, this used up all their fat reserves and they died of starvation. With study researchers realized it was a little more complex. The fungus invades the skin of the wings, and fighting that infection already uses up the bats’ energy and causes changes in blood chemistry. The damage and excess carbon dioxide building up in the blood causes the bats to wake more frequently, and the increased activity and loss of water and electrolytes through the lesions results in their death by starvation and dehydration.

Estimates are that as of 2012, between 5.7 and 6.7 million bats have died. Undoubtedly, it’s many more by now. Consider that each bat eats roughly a thousand insects an hour, which means in a nine-hour early summer night, a thousand bats would eat about nine million insects. In one night. Six million bats would eat 54 billion insects per night. Every night. Except they won’t because they’re gone, and a couple of million pounds of assorted insects fly around uneaten. When it comes to our food supply, health, and summertime comfort, the bats are on our side.

As long expected, white nose syndrome was identified on a few northern long-eared bats in a single cave in southwest Wisconsin. Whatever needed to be done to conserve bats was going to be done in this state too.

Clearly, supporting a robust bat population is in our best human interest. But how do we do that in the face of a disease that is easily transmitted and 90-95% fatal? Anything we can reasonably do should be done, one might think, especially to prevent transmission.

The United States Fish and Wildlife Service is a federal agency charged with looking out for the wildlife of our America. Other agencies such as the Park Service and the Forest Service have responsibilities in that area, but for the USFWS it’s the main deal.

bats_2Managing any species has a couple of major considerations. How are people to treat members of the species? Hunt them? Kills them only if they are problems? Feed them? What if a person’s usual activities result in occasional harm to members of the species? Consequences or none?
What about species habitat? Do we destroy it with impunity? Preserve it voluntarily? Preserve it with incentive? Preserve it by regulation with the force of law?

Buy it up and set it aside?

These are the questions the USFWS has to consider in the case of every species, and the Endangered Species Act gives them quite a bit of power to enforce what they decide.

Of course, this is government we are talking about here, so no decision is made in a sealed room. Politics are always howling outside the door. But still the USFWS has a fair amount of discretion in regulations it writes around an endangered species though it must subject anything major to the comments of the public, the scrutiny of its representatives and the limits of its budget.

If you are as old as I am, you may remember the “snail darter,” a tiny fish apparently found only in the upper reaches of Tennessee’s Tellico River that the state wanted to drown behind a dam. That little critter held up that dam project until it collapsed of its own inertia. For some it became an archetype for material progress halted by an insignificant species of very few individuals. It didn’t help when the fish was later discovered in a couple of other streams.

What the USFWS is proposing for the northern long-eared bat is a set of regulations that limit what can be done within a quarter of a mile of places where the bats hibernate. Other limitations affect the forest areas the bats use for roosting in the summer.

Also limited is cave touring and exploration in sites where the bats are known to be.

Now these would be logical steps to take if you believed as the USFWS scientists do that white nose syndrome can be transmitted by human traffic into the caves and bats can be disturbed by any loud and disruptive activity in the vicinity of their hibernacula and roosts. And if the bats are so valuable to people as they seem to be for controlling insects, who could object to rules that keep them safe?

It turns out that two particular groups object to some aspects of these proposed new regulations: loggers who want to cut trees on land near caves, and cavers, people who want to go in the caves. Both feel their rights are being trampled, and they both make a case that the rules are unnecessarily strict.

Next time we’ll take a look at this controversy, which seems to me a microcosm of the conflict between conservation and human plans that plays out time and again. Can these bats be saved? And will these regulations be the means by which they might be?

We won’t know those things by next issue, but we’ll see why the different stakeholders believe the way they do. Stay tuned.

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