What is white-nose syndrome (WNS)?
||Little brown bat with white-nose syndrome in Greeley Mine, Vermont, March 26, 2009
Photo by: Marvin Moriarty/USFWS
White-nose syndrome is a disease that was first documented at a cave in eastern New York in February 2006. Since that time, WNS has rapidly spread to multiple sites throughout the Northeast, Southeast, Midwest and Canada. As of May 2010, WNS has been confirmed from New Hampshire south to Virginia to Tennessee and is also suspected in Missouri and Oklahoma. WNS has been confirmed in two Canadian Provinces. Since its discovery in 2006, WNS is estimated to have caused the death of more than 1 million bats in the U.S. Researchers associate WNS with a newly identified fungus, Geomyces destructans, that thrives in cold and humid conditions characteristic of caves and mines where bats hibernate. The disease is named for the white fungus on the muzzles and skin of affected bats. Bats affected with WNS may have obvious fungal growth on their muzzles and/or wing membranes or display unusual behaviors (flying on cold winter days), but this is not always the case.
How does WNS kill bats?
Bats depend on fat reserves to survive winter hibernation. The fungus leads to bats being awakened from hibernation too often. Researchers believe that bats with WNS use up fat reserves faster and essentially die of starvation. Affected bats often leave their hibernacula during winter, to search for food. In some hibernacula death rates have been 90-100 percent.
How is WNS transmitted?
Bat-to-bat transmission has been verified and is considered the most common pathway. Affected sites generally follow bat migration routes. There is a strong possibility that WNS may also be transmitted by people inadvertently carrying the fungus from cave to cave on shoes, clothing and gear.
Will WNS spread to AZ?
We don’t know if WNS will spread to Arizona. The fungus can potentially be spread between bat hibernation caves in two ways: as an unwanted hitch-hiker upon humans, their clothing, or gear and from contact between bats. Of the 28 species of bats found in Arizona, approximately half hibernate. We do not have a lot of information about Arizona’s winter bat roosts. Arizona’s hibernacula are different from those in the east in that we tend to have smaller, dispersed groups of hibernating bats vs. large colonies that number in the thousands. It may be that there are large hibernacula out there that we don’t know about, but some of our hibernating species use rock crevices where they are difficult to detect and many hibernate in small groups of 50 or fewer. Many of our hibernating species are active periodically during the winter, and may eat and drink on warm winter days. About half of our bat species don’t hibernate, they migrate or are active throughout the winter. We are unaware of any especially large hibernacula in Arizona; our largest known winter colony is of ~1500 cave myotis. We do know that Arizona has cold, humid caves and mines that could potentially harbor the Geomyces fungus. We also know that two of the species of bats that have been affected by WNS are found in Arizona, and several other Arizona bats could be at risk as well.
Which bat species has WNS affected?
Little brown myotis (Myotis lucifugus), big brown bat (Eptesicus fuscus), tri-colored bat (Perimyotis subflavus), northern myotis (Myotis septentrionalis), eastern small-footed myotis (Myotis leibii), and the endangered Indiana myotis (Myotis sodalis). Three species have been detected with the WNS-associated fungus: gray bat (Myotis grisescens), southeastern bat (Myotis austroriparius), and cave myotis (Myotis velifer). Of these species, big brown bats and cave myotis occur in Arizona. Myotis bats have been especially hard hit in the east and Arizona has nine species of Myotis.
Does WNS affect humans or other wildlife?
There have been no reported illnesses attributable to WNS. Authorities urge taking precautions and not exposing yourself unnecessarily to WNS. Scientists use protected clothing when entering caves or handling bats.
What are the signs of WNS?
According to the Fish and Wildlife Service, WNS may be associated with some or all of the following unusual bat behaviors:
- White fungus, especially on the bat’s nose, but also on the wings, ears or tail.
- Bats flying outside during the day in temperatures at or below freezing.
- Bats clustered near the entrance of hibernacula.
- Dead or dying bats on the ground or on buildings, trees or other structures.
- Hibernating bats may have white fungus that is not associated with WNS. If a bat with fungus is not in an affected area and has no other signs of WNS, it may not have white-nose syndrome.
Why are bats important?
Bats play a very important role in the ecosystem. Bats are the main consumers of night-flying insects, including mosquitoes, beetles, moths and other human, agricultural, and forest pests. Two of Arizona’s bats are important pollinators of columnar cactus and other desert plants like Agave. Bats are also important in the ecology of caves, their droppings provide nutrients on which other organisms depend. Arizona’s diverse bat species include aerial insectivores (those that catch prey in midair), gleaning bats (those that pick insects off vegetation), and terrestrial feeding bats (those that prey on ground-dwelling insects, scorpions, and centipedes).
What is being done in Arizona?
The Arizona Game and Fish Department is working with other states and federal agencies to develop management strategies to prevent or slow the movement of WNS to Arizona. Ensuring that WNS does not arrive by people inadvertently carrying it on footwear or gear is of utmost importance. We urge cavers and other recreationists to reduce trips to Arizona caves and follow U.S. Fish and Wildlife Service protocol for disinfecting clothes and gear. The Department is developing a WNS response plan that will be simple and flexible, designed to raise awareness and prevent or slow the spread of the disease into Arizona and will include information on reporting and testing bats, and surveillance and monitoring.
What are other wildlife agencies and organizations doing?
An extensive network of state and federal agencies, universities, caving grottos and private individuals are working to investigate the source, spread and cause of bat deaths associated with WNS, and to develop management strategies to minimize the impacts. The overall investigation has three primary focus areas: research, monitoring and management, and outreach. Research topics vary from possible control measures to decontamination protocols, infection trials and sampling to determine how widespread the fungus is in the soil.
What can I do?
- Reduce the risk of spreading this disease, don’t go in caves and abandoned mines.
- Never wear clothing or use gear from affected areas in Arizona caves and mines.
- Decontaminate! Protocol details are at www.fws.gov/WhiteNoseSyndrome/cavers.html.
- Help spread the word about WNS.
Report unusual bat deaths to the Arizona Game and Fish Department at firstname.lastname@example.org or (623)236-7574.
What if I find dead or dying bats in winter or early spring, or observe bats with signs of WNS?
In Arizona, contact Angie McIntire, Bat Management Coordinator at email@example.com (623) 236-7574. If possible, photograph the potentially affected bats (including close-up shots) and send the photograph and a report that includes location (address or GPS) and a description of the circumstances.
If you need to dispose of a dead bat found on your property, pick it up with a plastic bag over your hand or use disposable gloves. Place the bat and the bag into another plastic bag, spray with disinfectant, close the bag securely, and dispose of it with your garbage. Thoroughly wash your hands and any clothing that comes into contact with the bat.
If you see a band on the wing or a small device with an antenna on the back of a bat (living or dead), contact the Arizona Game and Fish Department at firstname.lastname@example.org or (623) 236-7574. These band and transmitters are tools for biologists to identify individual bats.
White-Nose Syndrome - U.S. Fish & Wildlife Service
Bat Conservation International