Bats are facing an epidemic of their own: White-Nose Syndrome

A white-gloved hand hold a tawny colored bat with a white substance on it's nose.

A tri-colored bat displays symptoms of white-nose syndrome at from Chickamauga and Chattanooga National Military Park, Georgia (National Park Services/ Flickr https://creativecommons.org/licenses/by/2.0/)

By now, it comes as no surprise to hear that bats carry viruses. Between the current COVID pandemic, MERS, and SARS, all of which have been linked to bat transmission, the public eye isn’t exactly favoring bats. But bats are dealing with an epidemic of their own. White-nose syndrome, a condition caused by a fungus known as Pd, is ravaging bat populations across the United States. But while much of the nation has been able to take advantage of promising vaccines against their disease, the same can not be said for America’s dwindling numbers of bats. I spoke with white-nose syndrome experts to learn more.

 


Podcast Transcription:

Helen Bradshaw  0:02 
What bat data scientist Tina Chang remembers most about visiting bats in Virginia isn't seeing the scary creatures of Halloween stories, or even the sweet animals of children's picture books. What she remembers is the overwhelming number of dead bats from white-nose syndrome.

Tina Cheng  0:20 
It's really heartbreaking to walk in and see these sick bats. Sometimes you would find carcasses in caves as well. And these were, this was especially devastating, going to some caves where are these biologists that come for years. They go to these spots and they know exactly where the bats are because they come back every year. And we would return with these researchers and not only with the bats not be there, but we would see bones on the floor. And that was also really heartbreaking.

Helen Bradshaw  0:54 
Amid the bat linked pandemic that spread between people across the world, COVID-19, bats in the US are facing an epidemic of their own with white-nose syndrome. Since the discovery of white-nose syndrome in upstate New York in 2006, potentially 10s of millions of bats across the country have died. White-nose syndrome attacks hibernating bats in the form of a fungus pseudogymnoascus destructans, known as PD. This fungus then attaches spores of itself to the bats. These spores are what we see as the white fuzz on bats' noses, hence the name. But how does a little white fuzz on a bat's nose cause so much death?

Rich Geboy  1:34 
Yeah, so that's a great question.

Helen Bradshaw  1:37 
That's the US Fish and Wildlife's white-nose syndrome coordinator for the Midwest, Rich Geboy.

Rich Geboy  1:43 
The bats themselves typically will acquire a white fuzz on their muzzle or on their wings. And as it grows into the tissue of the bat's muzzle, or the wing, or the tail membrane, that will then become set in the effects of the disease.

Helen Bradshaw  2:05 
The effect of the disease, Cheng says in blunter terms, is that it causes the bats to come out of torpor in the winter when they aren't supposed to and...

Tina Cheng  2:14 
and then they burn through their fat reserves. And many of them die of starvation.

Helen Bradshaw  2:19 
But Mammoth Cave Resource Management Specialist, Rickard Toomey, says there is hope in the form of vaccination. 

Rickard Toomey  2:27 
There are tons of people working on cures, mitigations, vaccines, probiotics, all sorts of different approaches, trying to do exactly that: make the bats more immune.

Helen Bradshaw  2:45 
Cheng and Geboy say these vaccines and probiotics have not been developed nearly as quickly as our own COVID-19 vaccines or shown as encouraging of results.

Tina Cheng  2:55 
So there have been several probiotics that were under investigation and brought to different levels of trial. So I helped to work on one that's a bacterial probiotic, it's naturally found on the skin of bats. And the idea is just to try and amplify that on the skin of bats to provide some type of protection. There have not been any trials, including the one that I worked on, which has shown an increase in survival yet. It's not to say that this type of intervention is not fruitful or worth continuing. But it has not yet shown really promising results. 

Rich Geboy  3:43 
There have been a number of scientists looking at this out of the National Wildlife Health Center in Madison, Wisconsin, essentially trying to develop this vaccine. And with the eventual hope of leading to increased survival from bats. At this point, it's not there, but they're still in the development phase of that.

Helen Bradshaw  4:06 
But dissemination of these medicines would be tricky. America's millions of bats can't just book an appointment for a shot. 

Tina Cheng  4:14 
I think the idea was to get the vaccine in some kind of spray, and then to spray it on bats and then when they groom themselves, which they do quite a bit, then they would ingest the oral vaccine and get vaccinated.

Helen Bradshaw  4:28 
In the meantime, precautions have been put into action in places like Mammoth Cave. At this point, these measures are less so for keeping white-nose syndrome out as they are for keeping it in. Park visitor Alex Weaver experienced the bleach bath journey firsthand.

Alex Weaver  4:43 
So as I saw the, the little thing that we walked through, I was I was kind of confused. I was like I just I don't know what these are for. So I wasn't sure if it was more for the protection of the people or agriculture outside of the caves. But after a little bit of questions, I realized this for the bats. I don't really see too many bats while I was down there. But I figured they, they need protection just like anybody else. So it's got to follow the little bat rules.

Helen Bradshaw  5:15 
Anti-bat sentiment from the pandemic, and the fact that bats are the primary carrier of rabies in the state of Illinois, aren't helping awareness or support for a cure either. Author and journalist David Quammen, of Outsider Magazine and the New York Times, says an international fear of bats has deep historical roots, largely based on false information.

David Quammen  5:35 
In some cultures, there are these negative impressions of bats, fears of bats, because they are peculiar. They are mammals that fly. Bats, in fact, do carry a lot of different kinds of viruses, of which rabies is the most famous and the most scary, because it has the highest case fatality rate. But the fact is that if we leave bats alone, then there's very, very, very little chance of us getting infected with their viruses. There was a concern that this pandemic not be turned into another excuse for persecuting bats. Because there is a high likelihood that this virus originated in a form of bat and the bat didn't come looking for a human. Humans, in some way, still undiscovered, put themselves in a situation where they, they gave the virus an opportunity to spill over from a bat into a human fatefully.

Helen Bradshaw  6:40 
Even if an effective vaccine or probiotic is developed, and even if it's successfully administered, it's possible not all the bats can be saved in time. Cornell says white nose syndrome has a mortality rate of 90 to 100% among some species of hibernating bats, meaning until a treatment is implemented, bat species like the northern long-eared bat are at risk of extinction.

Rickard Toomey  7:02 
In 2004, 2005, we had a big bath survey, and northern long-eared bats were almost 50% of the bats caught on the park in the summer. 800 bats were caught. Post white-nose, we caught I think two of them. Our catch rate on northern long-eared bats went down 99.7%. Northern long-eared bats on Mammoth Cave National Park are functionally extirpated.

Helen Bradshaw  7:39 
While some areas hit by white-nose syndrome have stabilizing populations of little brown bats, the future of North American bats is uncertain.

Tina Cheng  7:47 
There are other species that have not recovered, that are not stabilized, that have gone sometimes to zero, and will likely never come back.

Transcribed by https://otter.ai

 

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