White-nose Syndrome in bats

White-nose syndrome is fungal disease caused by Pseudogymnoascus destructans. The fungus appears as white fuzzy growth on the wings, ears, face, and tail membranes of afflicted bats. The Pd fungus shows optimal growth at 54.5-60.4 F (12.5-15.8 C) which is similar to temperatures found in bat hibernacula. The fungus is capable of invading the skin of bats during hibernation when bat body temperature is significantly lowered and the immune response is suppressed.

Commonly Affected Species:

Signs Of Disease

The fungus that causes WNS affects the ability of bats to hibernate. It appears to alter behavior of bats resulting in delayed arousal from torpor following disturbance, aberrant behavior including increased activity during normal hibernation periods or roosting in abnormal sites. Susceptible bat species may exhibit high levels of winter mortality in and around hibernacula. Bats affected by WNS usually have white or gray powdery fungus growing on the muzzle, ears, wings and tail membranes and may be in thin body condition and dehydrated. Wing damage (thin membranes, depigmented areas, holes, tears, flakey skin) may be seen on affected bats.

Where is Disease Found?

The fungus that causes WNS is endemic in Europe and Asia but illness and death in bats there is minimal compared to North America. In the US, the presence of WNS in bats was initially detected in a cave in New York in winter 2006-2007. Since then, millions of bats have died as the disease has spread over most of eastern North America. WNS has reported from 31 states and 5 Canadian provinces and the fungus has been confirmed in bat hibernacula in two additional states. In March 2016 WNS was found in a Little Brown Myotis in Washington and subsequently WNS or Pd have been found in Yuma Myotis and Silver-haired bats.

How Can I Protect Myself?

The fungus that causes WNS in bats is not known to be a pathogen for humans or other animals.

Samples to Collect

Bats that are observed with unusual behavior or mortality events involving 5 or more dead or sick bats at one location over 1-2 weeks should be reported to the Idaho Department of Fish and Game. Take good quality pictures of affected sick or dead bats. Bats should not be handled without appropriate training and vaccination for rabies. If there is concern about this condition, contact a conservation officer or an Idaho Department of Fish and Game Regional Office. Appropriate samples can be collected for testing if deemed necessary. If authorized, live bats can be collected as appropriate and dead bats can be collected and kept cool until they can be submitted to local Idaho Department of Fish and Game officers or regional offices.

Can I Eat The Meat?

No. Bats are legally protected in Idaho and classified as Protected Nongame Species (IDAPA 13.01.06). They cannot be taken or possessed at any time or in any manner except as provided in Idaho Code (IC 36-106(e), 36-401, and 36-1107), Commission rule, or IDAPA 13.01.10.

What is IDFG doing to help manage this disease?:

White-nose syndrome and Pd have not been detected in Idaho. However, Idaho Department of Fish and Game is conducting winter hibernacula surveys and responding to reports of bats with abnormal behavior or mortality events.

Bats are an essential and beneficial part of the ecosystem and serve as keystone species for cave habitats. Bats play critical roles in insect control, plant pollination, seed dissemination, cave ecosystems, and provide food for other animals contributing substantially to the economy of Idaho.

Some aspects of the geographic spread of WNS suggest that humans that visit caves and mines may transmit the fungus from infected sites to clean, uninfected sites. Clothing and equipment that are exposed to fungal infected environments are a potential mechanism for spreading Pd, even during the summer when Pd prevalence is low. Because of the devastating effects of WNS, it is critical that people assume responsibility for the potential spread of WNS and take precautions to avoid inadvertent transport of Pd to uncontaminated bats, caves or mines.

For protection of bats and their habitats, the following recommendations should be followed. Comply with all current cave and mine closures, advisories, and regulations on federal, state, tribal and private lands. Follow the current decontamination guidelines for decontamination of clothing and equipment used in caves and mines. Do not transport any clothing, footwear, equipment or gear into or out of Idaho that has been in contact with bats or their environments. Do not use ANY gear or clothing in the western US that has been used in caves, bat hibernaculum or roosts east of the Mississippi River. Clean and disinfect all gear and clothing used in western caves and roosts before entering any other caves or roosts in the west.

Decontamination options include submersion in hot water (131 F or 55 C) for 20 minutes or soaking equipment for at least 10 minutes in a 10% bleach solution, Lysol all-purpose professional cleaner, or Formula 409 as per the WNS Decontamination Protocol.

How do I learn more about this disease?