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BLM & Grotto Group Partner to Protect Bats

White-Nose Syndrome

Little brown bat with white-nose syndrome in Greeley Mine, Vermont, March 26, 2009. Photo by Marvin Moriarty, USFWS.
Little brown bat with white-nose syndrome in Greeley Mine, Vermont, March 26, 2009. Photo by Marvin Moriarty, USFWS.
Little brown bat with white-nose syndrome in Greeley Mine, Vermont, March 26, 2009. Photo by Marvin Moriarty, USFWS.
Photos by Marvin Moriarty, U.S. Fish & Wildlife Service.

What is White-Nose Syndrome?

White-Nose Syndrome (WNS) is a fungal disease that has killed more than 5.5 million bats in the eastern third of North America during the past six years and continues to spread south and west. Cave-hibernating bats are especially vulnerable because underground caves and mines provide the cool, moist conditions favorable for the fungus to thrive.

Bats with WNS may exhibit a white fungus that is found around the muzzle, ears, or wings of affected individuals. Other symptoms are displayed. For example, bats have been found moving to the entrance of the caves and often coming out of the caves and flying around in the middle of the day during winter months. Bats displaying this abnormal behavior have reduced fat reserves. Although it is normal for bats to occasionally interrupt their winter roosting, they are not equipped to withstand the drain on their fat reserves resulting from flying more often and during the day, a behavior thought to be caused by the irritation of the fungus. Many bats are non-responsive and many have been found dead both inside and outside caves.

How is White-Nose Syndrome Spread?

  • Bat to Bat - Bat to bat transmission of Geomyces destructans has been documented in lab conditions and the geographic pattern of spread appears to support lab findings. It is also possible that other unknown agents associated with WNS are spread bat to bat.
  • Cave to Humans to Bats - Aspects of the geographic spread suggest that humans may transmit WNS from infected sites to clean sites. This kind of spread is most likely occurring from clothing and equipment that are not properly cleaned and decontaminated between sites. Formal testing of human spread WNS is ongoing. Because of the devastating effects of WNS, it is critical that people assume responsibility for the potential spread of WNS.

Signs of WNS

  • White fungus growing on the nose, wings, ears, and/or tail membrane.
  • Bats flying outside during the day in winter.
  • Bats clustered during winter in sections of caves and mines not normally used for winter roosts, especially near the entrance.
  • Dead or dying bats on the ground or on buildings, trees or other structures during the winter.
  • Bats not arousing at all after being disturbed.

Bats Need Your Help

  • Report unusual bat behavior to the local Bureau of Land Management office, your state wildlife agency, the U.S. Fish and Wildlife Service or Forest Service. Unusual behaviors may include daytime flight, especially during very cold weather. Report dead or dying bats found on the ground, trees, or buildings.
  • Do not enter any Wyoming caves or mines sites unless all clothing and equipment has been de-contaminated according to outlined procedures. Do not use any clothing or equipment that has been previously used in states where White Nosed Syndrome has occurred at any Wyoming sites.
  • Report unauthorized cave and abandoned mine entry to your local BLM office.

Bats in Wyoming

  • There are 16 species of bats on BLM-administered public lands in Wyoming, 12 of which are common. The remaining four species are very uncommon and have not been observed or documented in Wyoming except on rare occasions.
  • Wyoming bats can roost in trees, caves, abandoned mines, bridges or even buildings. 
    • Tree roosting bats include: hoary bats, Eastern and Western red bats, Northern myotis and silver-haired bats.
    • Bats commonly found in Wyoming caves or mines include: little brown myotis, small-footed myotis, long-eared myotis, fringed myotis, long-legged myotis, big brown, pallid, Townsend's big-eared and spotted bats.
    • Bats that have only been incidental to Wyoming include: Yuma myotis, California myotis, Brazilian free-tailed, Eastern pipistrelle and big free-tailed. These primarily occur south and east of Wyoming but sometimes drift into the state along the fringes. They are not known to have any hibernation or maternity locations in Wyoming.
  • All of Wyoming's bats have been protected since 1994, when a non-game wildlife regulation was enacted by the Wyoming Game and Fish Commission. 

BLM Policy

Where can I find out more about WNS and bats?