White-nose syndrome

Closeup photo of a Little brown bat with a damaged wing caused by the fungus
Little brown bat found in western Washington in March 2016.
The fungus damaged the bat’s wings making it unable to fly.Progressive Animal Welfare Society (PAWS)

White-nose syndrome has killed millions of bats in eastern North America since 2006. Washington's first case of the disease was confirmed in March 2016 near North Bend in King County.

Bat observation reports

 

 

What is white-nose syndrome?

Image showing a normal Little brown bat wing
Normal wing of little brown bat.

White-nose syndrome is a disease caused by the fungus Pseudogymnoascus destructans. The disease is estimated to have killed millions of bats in eastern North America since 2006 and can kill up to 100% of bats in a colony during hibernation.

In March 2016, the first case of white-nose syndrome in the western U.S. was confirmed in a little brown bat (Myotis lucifugus) near North Bend in King County. Though the disease has devastated bat populations in eastern North America, we do not yet know how it will impact western bats. In general, bats in Washington do not hibernate in large groups like eastern North American bats. Thus, the spread of the disease in western states may be different.

Image showing severe damage from infection caused by white-nose syndrom
Little brown bat with skin infection on wing.Progressive Animal Welfare Society (PAWS)

The fungus can grow on the nose, wings, and ears of an infected bat during winter hibernation, giving it a white, fuzzy appearance. Once the bats wake from hibernation, this fuzzy white appearance goes away. Even though the fungus may not be visible, it invades deep skin tissues and causes extensive damage.

Affected bats arouse more often during hibernation which causes them to use crucial fat reserves, leading to possible starvation and death. Additional causes of mortality from the disease include wing damage, inability to regulate body temperature, breathing disruptions, and dehydration.

How the fungus spreads

Map showing spread of white-nose syndrome in North America
White-nose syndrome has spread to 33 states and seven Canadian provinceswhitenosesyndrome.org

The fungus that causes white-nose syndrome is harmful to bats but not humans, livestock, or pets.

Though the fungus is believed to be primarily transferred via bat-to-bat or bat-to-environment contact, it can also be inadvertently spread by humans. People can carry fungal spores on clothing, shoes, or recreation equipment that comes into contact with the fungus. Properly decontaminating shoes, clothes, and equipment used in areas where bats live is critical to reduce the risk of spreading white-nose syndrome.

The fungus can survive in the environment of underground hibernacula (like caves and mines) for years, and scientists are currently researching how persistent it is in other environments where bats roost such as cliffs, attics, or under bridges.

Winter hibernating areas may serve as reservoirs for the fungus. Bats that use or even briefly visit these hibernating spots could deposit or pick up the fungus and move it to other areas where bats live. Identifying these types of environmental hot spots for the fungus, and how bats may be coming in contact with and moving the fungus across the landscape, is an important part of reducing the spread of white-nose syndrome in Washington bats.

How you can help

  • Report groups of bats you see using the online observation reporting form. This information will help us understand our bat populations and monitor white-nose syndrome in Washington.
  • Do not handle live bats. If you have found a sick or dead bat, please report it using the online reporting form.
  • Avoid entering areas where bats may be living to limit the potential of transmitting the fungus that causes the disease and disturbing vulnerable bats. Do not allow pets to access areas where bats may be roosting or overwintering as they may carry the fungus to new sites.
  • Get involved in bat conservation! Help improve bat habitats by reducing lighting around your home, minimize tree clearing, and protect streams and wetlands. Try to incorporate one or more snags into your landscape, keeping old and damaged trees when possible. Snags provide important habitat for bats and other backyard wildlife. For more information on living with bats, and instructions for how to build a bat house, download the "Living with Wildlife: Bats" publication.

Why bats matter to our environment and economy

Bats are valuable members of ecosystems around the world, saving farmers in the U.S. alone over $3 billion annually in pest control services. One colony of bats can consume many tons of insects that would otherwise consume valuable crops, or threaten human health and well-being. Some bat species eat moths or beetles that are harmful forest pests.

Timeline of fungus and white-nose syndrome detection in Washington

Note: Some bat species are affected by white-nose syndrome while others may only carry the fungus that causes white-nose syndrome (Pseudogmynoascus destructans [Pd]), and not show any symptoms of the disease.

 

March 2016

  • A little brown bat (Myotis lucifugus) was found alive on a trail by a hiker near North Bend in King County. A veterinarian from Progressive Animal Welfare Society (PAWS) noticed clinical signs of white-nose syndrome, including dehydrated, wrinkled wings. Testing at the National Wildlife Health center confirmed the bat had white-nose syndrome.
  • A silver-haired bat (Lasionycteris noctivagans) found near Seattle in King County tested positive for the fungus that causes white-nose syndrome.

July 2016

  • Guano (bat feces) collected from under a bridge frequented by bats near North Bend in King County tested positive for the fungus that causes white-nose syndrome.

April 2017

  • A Yuma myotis (Myotis yumanensis) and a little brown bat were found on separate occasions near North Bend in King County. Lab tests confirmed that these bats had white-nose syndrome.

May 2017

  • Guano collected from a maternity roost near North Bend in King County tested positive for the fungus that causes white-nose syndrome.
  • Researchers collected samples from bats at Mount Rainier National Park in Lewis County. Lab results showed two little brown bats and two Yuma myotis tested positive for the fungus that causes white-nose syndrome.

July 2017

  • Guano (bat feces) collected from under the same bridge sampled in July 2016 tested positive for the fungus that causes white-nose syndrome.

January 2018

  • A little brown bat found near Seattle in King County tested positive for white-nose syndrome.
  • A little brown bat found near North Bend in King County, the same location as the bats confirmed with white-nose syndrome in April 2017, tested positive for white-nose syndrome.
  • A little brown bat and Yuma myotis found in King County were submitted to the Department of Health for rabies testing. The bats tested negative for rabies, but positive for the fungus that causes white-nose syndrome.

March 2018

  • A Yuma myotis found near North Bend in King County tested positive for white-nose syndrome.

April 2018

  • Four little brown bats or Yuma myotis (species are difficult to distinguish visually) found near North Bend in King County tested positive for the fungus that causes white-nose syndrome. The bats showed symptoms of the disease white-nose syndrome, but researchers were unable to confirm if they were positive. Samples collected from the bat roost also tested positive for the fungus that causes white-nose syndrome.
  • Eight Yuma myotis captured near North Bend in King County tested positive for the fungus that causes white-nose syndrome. The bats showed symptoms of the disease white-nose syndrome, but researchers were unable to confirm if they were positive. Samples collected from the bat roost also tested positive for the fungus that causes white-nose syndrome.
  • A little brown bat or Yuma myotis (species are difficult to distinguish visually) found near Renton in King County was submitted to the Department of Health for rabies testing. The bat tested negative for rabies, but positive for white-nose syndrome.
  • A little brown bat or Yuma myotis (species are difficult to distinguish visually) found near Maple Valley in King County was submitted to a wildlife rehabilitator associated with Raindancer Wild Bird Rescue. The bat tested positive for white-nose syndrome.
  • A little brown bat or Yuma myotis (species are difficult to distinguish visually) found at a maternity colony near North Bend in King County tested positive for white-nose syndrome.

May 2018

  • Guano (bat feces) samples collected from a little brown bat and Yuma myotis colony near Issaquah in King County tested positive for the fungus that causes white-nose syndrome.
  • Environmental samples collected under a bridge frequented by bats in Lewis County tested positive for the fungus that causes white-nose syndrome.
  • Three little brown bats or Yuma myotis (species are difficult to distinguish visually) found near North Bend in King County tested positive for white-nose syndrome.

March 2019

  • Five little brown bats or Yuma myotis (species are difficult to distinguish visually) found in King County tested positive for white-nose syndrome.
  • A western long-eared myotis (Myotis evotis) found in King County tested positive for white-nose syndrome. This is the first time this species has been confirmed with the disease in North America.
  • A little brown bat found in Pierce County tested positive for white-nose syndrome. This is the first case of white-nose syndrome in Washington outside of King County.