Adventuring through natural caves and nonactive mines in Colorado have been popular hobbies and destinations for spelunkers and tourists alike. However, plans for cave exploration have been put on hold in order to protect one of nature's most misunderstood creatures: bats.
North American bats are under attack by the white nose syndrome, Geomyces destructans, a fungus originating in Europe that is already established and prevalent through the Northeast and South United States. Over 1 million bat fatalities have been reported due to white nose syndrome, and the worry in the West is that the disease will soon migrate this way.
Bats are a vital component to their ecosystems, acting as pollinators, seed dispersers, a food source for predators, and pest controllers, as they eat thousands of insects a night. In the winter, they hibernate in dark, moist environments where their metabolism slows down and their immune system virtually shuts down for the season. This is when the fungus attacks. Both organisms seek out caves with temperatures ranging from 41 to 59 degrees Fahrenheit, with at least 90 percent humidity.
Affected bats show signs of white powder on the nose, ears and wings. The fungus irritates the bat and wakes it from hibernation. The bats prematurely use up fat stored for the whole winter, and the unnatural extra activity results in starvation. So far this has been observed among little brown bats, northern long-eared bats, and the already endangered Indiana brown bat. Two other species, the Ozark big eared bat and the Virginia big eared bat, are on the endangered species list and at a high risk of contracting white nose syndrome.
Since the discovery of white nose syndrome in the U.S. in the winter of 2006-07, research has been inconclusive that humans play a role in the spread of the fungus that causes white nose syndrome. Through research it is now certain that the primary vector for the spread of the fungus Geomyces destructans is bat to bat, with the secondary vector being from cave to bat. While there has been suspicion of human assistance to the spread of the fungus in instances with long-distance jumps, none have been directly tied to the work of visitors to caves.
Those who obtain permits to handle bats for research and conservation practices must follow protocols established by the U.S. Fish and Wildlife Service. The protocols can be found on the U.S. Fish and Wildlife Service website, and include rules such as:
• No gear/clothing can be used east of the Mississippi River and reused out West without proper disinfection with bleach or professional Lysol agents.
• Dead bats, bats with radio collars, or tagged bats must be reported to the U.S. Fish and Wildlife Service for species counts.
• Never handle a bat without a disease transmission barrier, due to bats sometimes carrying the rabies virus.
Until we can learn more about white nose syndrome, caves will remain closed in the Rocky Mountain region and foothills including Colorado, Wyoming, South Dakota, Nebraska, and Kansas. This refers only to caves and abandoned mines on U.S. Forest Service lands. This closure is not applicable to commercial or privately owned caves.
A severe decline in our populations of bat species in the United States could potentially alter and disrupt our natural ecosystems with permanent and damaging consequences.
Nikki Bauman is a naturalist at Walking Mountains Science Center. The new Avon Science and Nature Center offers free admission and is open to the public 10 a.m.-6 p.m. Monday through Saturday.