Local cave and mine closure aims at keeping people from infecting bats

Disease’s westward migration causes some concern

Finally the Caves Trail near Crested Butte South is starting to dry out and soon the pull-out on Cement Creek Road will be full of cars and people with dogs heading for the hills from dawn to dusk and beyond.

But before they get up to the caves, everyone passes the sign that’s been there for months: “Attention: Do Not Enter Cement Cr. Caves…” or any cave or abandoned mine on National Forest Service Lands. It shows a symbol meaning no spelunking, which shouldn’t be a problem in the Cement Creek caves.
But in an area rich with mining history, there is no shortage of opportunity to go underground or even just walk into a cave. So what’s the worry about?
In fact, the concern isn’t for human health at all, but the safety of the little brown bats that spend their winters hibernating in caverns around the country.
Those who follow the posted prompts to learn more about the warning learn that populations of the bats, mostly in the east, are under threat of White Nosed Syndrome, a disease that inhibits the animals’ ability to put on weight before winter, making it difficult to survive hibernation.
Already, since being discovered in a cave in upstate New York in 2006, the disease is thought to have killed some one million bats from one end of the Atlantic coast to the other, and it’s spreading.
“White-nose syndrome (WNS) is spread primarily through bat-to-bat contact. Most of the spread of WNS can be explained through normal bat movement between roosting, foraging and hibernation sites,” says U.S. Fish and Wildlife Service National White-Nose Syndrome communications leader Ann Froschauer.
But scientists are making a distinction between the disease and the fungus being associated with the disease, geomyces destructans, or GD, which has been found as far west as Missouri and Oklahoma. Froschauer regards that kind of distance as being “large geographic jumps from where the fungus and disease have likely spread through bat-to-bat contact.”
While most people think of bats as being the ones capable of spreading disease to humans, researchers believe the fungus can catch a ride from one cave to another on people’s clothing, shoes and gear, infecting the bats as they go.
And no matter where people go, there’s a chance that they’ll run into the little brown bat. Froschauer says the bats “are one of the most ubiquitous bat species, with a range that covers a large portion of North America, from central Alaska to central Mexico.”
Unfortunately, according to a report in the journal Science, some regional populations of the little brown bat could see complete collapse in the next two decades; some populations have already suffered 100 percent mortality.
Removing bats from an ecosystem could cause severe damage through an overabundance of the bugs that rank highest on the bats’ menu.
“Bats play a very important role in an ecosystem. The bats that are currently affected by WNS are all insectivorous—eating insects [including a variety of crop and forest pests]. Bats are the major predator for night-flying insects, and provide an important service in pest control,” Froschauer says.
The journal Science also recently reported that bats provide their hosts with nearly $23 billion in agricultural pest control. Although the pests threatening the local forests (mountain pine beetles) aren’t exactly agricultural in nature, they are a serious threat to the surrounding landscape and economy.
It would take little more than for someone wearing shoes at a cave in Oklahoma, where the GD fungus is on the ground, and then again in the Cement Creek caves or in an abandoned mine somewhere, for the disease to make the trip from there to here.
The disease isn’t confined to the little brown bat either, although they’re the species taking most of the heat for the spread of WNS. Of about 45 bat species found in the United States, 26 spend their winters and days in caves. According to the report in Science, the disease is known to have affected at least seven other species.
According to Froschauer, “Over 300 agencies and institutions are involved in the WNS investigation and response, and a national plan details the elements that are critical to the investigation and management of WNS, identifies key action items to address stated goals, and outlines the roles of agencies and entities involved in the WNS response.”
Caves and mines will be closed in the Rocky Mountain region until July 27 unless the order to keep them closed is extended. Grand Mesa Uncompahgre and Gunnison National Forest information services officer Roger Haga said the local office hasn’t yet been directed to maintain the closure.
But until more research is conducted, he says, “It’s bad for bats, it’s bad for ecosystems and therefore it’s bad for us.” So steer clear of caves and abandoned mines until then.