The fungus that causes a deadly bat disease now has been found in 21 Texas counties. Last year, the fungus was found in just 10 counties across the state. Texas Tech assistant professor in biological sciences Liam McGuire says the disease has not yet been detected in Texas. The same is true for Mississippi, Wyoming, North Dakota and California.
"This just might be a case of there’s a progression in terms in timing. We’ve seen in a variety of regions where we find the fungus in one year and it’s not until the second or maybe third year that we start to see the disease. And I don’t think it’s really well understood why that is. It just might take a certain amount of time for the environmental load of the pathogen to build up or something to that affect. So it could just be a matter of time.”
To date, the disease, which is caused by a fungus first discovered in the US in 2006, has been found in 33 US states and seven Canadian provinces. New fungus detections in Texas in 2019 include the first in East Texas in Liberty County, and the most southerly in the US in Frio and Victoria counties.
Researchers across North America are working to pin down a way to eradicate the fungus from naturally occurring caves and other places bats hibernate. Scientists are exploring the use of ultraviolet light, an oral vaccine for the bats, genomics, a probiotic, and manipulating the microclimates where bats are found.
“For a lot of these treatments that people are looking at these days are sort of the first stages of finding something that works and once that we’ve demonstrated that it works, then the next step is ‘Ok, how do we actually deploy it?’. And so, there’s different ideas that people have sort of thrown out there kind of like in formally or you know not in detail but we’re not quite at the point where we’ve got a particular treatment that where we can then really finalize the specifics of how you would deploy that at scale. There’s ideas, but that’s sort of a next step once you’ve got something that’s got something that shows good promises on being the thing to run with.”
The fungus was found while surveys of hibernating bats were being done in a New York cave in 2006. The fungus isn’t new to science and likes cold and humid places. After identifying the fungus in North America, researchers found it exists also in Old World places, like Europe and Asia.
McGuire says any treatment, once found, must be closely studied before use.
"Got be careful how you do these things, because you are interfering in a natural system. And you want to make sure what that whatever you’re going to do is going to be a net benefit, you know. Make sure that you’re not going to make things worse for the bats or for any of the other organisms that are out there. And this becomes a particular concern when you start talking about natural cave systems compared to, say, abandoned mines. A cave has been there and there are plenty of other organisms that live in those caves besides the bats. Just because the bats happen to be bigger and have a spine doesn’t necessarily mean that they should get some sort of preferential treatment compared to some of these other organisms that are living in these caves.”
Thus far, McGuire says, no bat species has gone extinct.
Researchers, he says, do have concerns about the bats in Texas who so far have only the fungus.
“Of particular concern is that several species that we’ve seen the fungus here in Texas are bats that get up and fly quite a long distance. The cave miotis, your Mexican Free-tail bats. They go a long way, and so these bats, although they themselves may not get the disease maybe really good job transferring the fungus across huge amounts of space, and so this may be a stepping stone that gets the fungus across the Great Plains and into the Rocky Mountain West and that’s certainly a concern.”
Millions of hibernating bats have died in the eastern parts of the US.
Bats play an important role in the ecosystem by consuming large numbers of insects. Recent studies have shown that the value of that insect control in Texas agriculture is $1.4 billion annually.
McGuire says that bats that have survived the disease for multiple years in the eastern part of the country need to be looked at carefully.
“There’s these remnant populations that have become really of great interest because that’s going to be the basis for any sort of recovery. It’s going to take a long, long, long time. These bats have very low reproductive rates. They only have one pup a year, but those are the individuals that are then going to then repopulate these areas. That might take hundreds of years to get there.”
McGuire says White-Nose Syndrome has not yet been identified in the state. The fungus’ detection in Frio and Victoria counties is the most southern in the US.
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