Here & Now

White Nose Syndrome Threatening Wisconsin Bats

Frederica Freyberg:

Now another Wisconsin wildlife story, this one a disease affecting the state's bat population. It’s called White-Nose Syndrome after the powder-like substance found on an infected bat's nose and wings. Last month the disorder was found in bats in a mine site in Grant County. The disease has killed 5 million bats in 23 states since 2006. The spread of the disease poses serious eco-threats according to our next guest from the DNR, bat specialist, Paul White. Paul, thanks for being here.

Paul White:

Thanks for having me.

Frederica Freyberg:

Was it really only a matter of time until this was found in bats in Wisconsin?

Paul White:

Unfortunately, yes. So we have been expecting this for some time. And every year that we would go in and do winter surveillance, we are expecting to find it. We really ramped up our efforts in 2010, and fortunately we haven’t found it until March 28 of this year.

Frederica Freyberg:

And you found it in just one cave in Grant County?

Paul White:

Yes, just one site in Grant County. We’ve since looked at a variety of sites close to that parameter, and we have not noticed it through swabbing efforts or any other visual evidence of the fungus.

Frederica Freyberg:

So is there some potential that it could be kept right to that one site or not?

Paul White:

At this point it’s a bit of a challenge to just try and isolate it to one area. And so there’s been a variety of techniques applied out East. But unfortunately, they have not found that those techniques are applicable to at least trying to mitigate the fungus to one site. So essentially these bats– It’s a reservoir right now, and unfortunately we see the disease spreading much more rapidly within the next coming years.

Frederica Freyberg:

I was just going to ask, what are the implications of this.

Paul White:

Yeah.

Frederica Freyberg:

In just Grant County to the entire population of bats in Wisconsin?

Paul White:

Sure. Well, Grant County, unfortunately, is in the southwest part of the state. We’ve got a lot of old mining activity. There’s caves that are in that area. So it really is a stepping-stone into Wisconsin, and then into our larger populations which are north of that still. But it really does serve as a stepping-stone into Wisconsin.

Frederica Freyberg:

What are Wisconsin’s bat populations like? How do they compare to other states?

Paul White:

Originally speaking, we have one of the largest hibernating little brown bat populations probably left in the world. I mean, if you look at the Northeast, their populations have been decimated to where they have not even anywhere close to what they used to have. And so we’re estimating anywhere from 350,000 to 500,000 bats that use Wisconsin as a wintering site.

Frederica Freyberg:

Why are bats important?

Paul White:

Everybody thinks of mosquitoes, and they certainly eat their share, but it makes up actually a relatively small portion of, at least, some of the bats’ diets. They can eat anywhere from 500 to 1,000 mosquito-sized insects in an hour. And that's– You’re removing a top predator of insects, whether it’s forest pests or agricultural pests. So when you look at that side of things, there was a recent study done in 2011 that showed if you removed bats from the landscape in Wisconsin, you can lose anywhere from $658 million to $1.5 billion worth of added annual cost that you would have to apply either pesticides or find other ways to mitigate now that you’ve got bats gone from the landscape.

Frederica Freyberg:

Where did this disease originate?

Paul White:

Well, it’s believed it hitchhiked either through human transmission, potentially, to New York. And that’s really the epicenter, in Howes Cavern in New York, and has since spread to 25 states and four Canadian provinces. That to be– That is the epicenter at this point.

Frederica Freyberg:

How does this White-Nose Syndrome affect the bat itself physically? Why does it kill it?

Paul White:

Sure. Well, bats use a strategy when they’re deciding to spend the winter in Wisconsin. That’s usually hibernation. So they’ll spend anywhere from 15 to 20 days sleeping. They’ll wake up every 15 to 20 days, groom themselves and go right back to sleep. They do that for six to eight months of the year. So what this fungus does it is causes the bats to wake up much more frequently and invades their skin tissue to the point where, it's definitely an irritant, but it affects a variety of thermal regulation and water transportation that the wings and the face allows too. So it causes the bats to wake up more frequently, anywhere from three to five days on average. And so it uses those fat reserves that they need to last six to eight months. They’re forced to either find insects or look for water that’s not available in the middle of January and February. So they’re basically dying in the landscape.

Frederica Freyberg:

Is this dangerous to humans or animals?

Paul White:

No. We’ve found there’s no– At this point there’s no evidence to suggest that it affects humans or pets or anyone.

Frederica Freyberg:

So what are people like you in the DNR and elsewhere doing to try to at least stem the rapid spread of this in Wisconsin?

Paul White:

Well, in 2011 we considered all our 4K bat species, which are the known species to be affected by White-Nose Syndrome, listed as threatened species within the state, which has some protection within there.. And making sure that people, if they have bats in their home, if they’re looking to get rid of bats in any way, that they have to go about it in the right way and then actually follow the time line which we have. There are other things that we try to do to at least try and limit the human-assisted transmission of it, and that's making sure that people follow proper decontamination protocols. So if you’re visiting a site, if either it's a commercial site or if it's a site that you're just visiting on your own, making sure that you’re not taking one possible evidence from one site into another. And so proper decontamination must be followed, especially us. We’re visiting a variety of these sites. We want to make sure we’re not the ones carrying this disease. Decontamination protocols, in general, are enforced. And all the sites, really, have control plans at this point, or prevention plans, to try to make sure that White-Nose doesn’t come in their site.

Frederica Freyberg:

All right. Paul White, thanks very much.

Paul White:

Thank you.