White-nose Syndrome and Minnesota's Bats

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What is white-nose syndrome?

 

White-nose syndrome (WNS) is a disease that is killing hibernating bats in eastern North America. It is believed that more than 5.7 million bats have died as a result of the disease, so far.

Named for the white fungus that was observed on noses of the first infected bats, it also affects other body parts. A newly discovered fungus, Pseudogymnoascus destructans, (formerly known as Geomyces destructans), has been demonstrated to cause WNS in bats. The fungus thrives in cold, humid conditions characteristic of the caves and mines that bats use to hibernate.

WNS was first documented New York in the winter of 2006-07. The disease continues to spread westward as shown in the map above.

 

 

How is WNS transmitted?

 

Scientists believe that WNS is transmitted primarily from bat to bat. Humans and other animals visiting infected caves and mines may inadvertently carry the fungus to unaffected caves. The fungus can remain in a cave after all the bats have died.

 

 

Is WNS dangerous to humans?

 

No. Bats appear to be the only animals that are susceptible to this disease.

 

 

What are signs of WNS?

 

Bats appear to die from WNS primarily during winter, due to starvation, physiological shock or freezing. During winter months, observable signs of WNS may include:

  • white fungus on the bat's muzzle and other hairless parts of the body, such as wings and tail

  • bats active outside during the day when temperatures are below freezing

  • bats clustered at the entrance of hibernacula

  • dead or dying bats on the ground or on buildings and trees

Note: The WNS fungus does not grow on bats during the warm weather months when bats are active. Also, other white fungi may grow on dead bats that are not associated with WNS.

 

 

What should you do if you find dead or dying bats, or if you observe bats with signs of WNS?

 

Contact the Minnesota Department of Natural Resources.

Photographs of the bat and details about its behavior or where and when it was found are very helpful.

Use caution when handling bats: Never handle live bats without gloves. If a person or pet has been exposed to a bite, scratch, or saliva from a live or dead bat, contact the local public health department for further guidance.

 

 

What species of bats are affected?

 

Seven bat species reside in Minnesota. Four hibernate in caves and mines and three migrate out of the state during winter. All four of the hibernating species have been shown to be affected by WNS in other states. These are Little Brown Myotis (Myotis lucifugus), Northern Long-eared Myotis (Myotis septentrionalis), Tricolored Bat (Perimyotis subflavus), and Big Brown Bat (Eptesicus fuscus).

 

What you can do

Further information

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