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Little brown bat found in western Washington in March 2016. The fungus damaged the bat’s wings making it unable to fly. Photo: Progressive Animal Welfare Society (PAWS)
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Since March 2016, when the first case of white-nose syndrome (WNS)
was confirmed in Washington State,
the Washington Department of Fish and Wildlife (WDFW) has collaborated with partners, including the National Park Service (NPS), to collect
samples from bats and the areas where they live. This proactive surveillance work helps researchers and wildlife managers
detect the presence of the fungus that causes white-nose syndrome
(Pseudogymnoascus destructans), and track the spread of this catastrophic bat disease.
In May 2017, NPS researchers swabbed the wings and muzzle of 24 live bats in a roosting area at Mount Rainier National
Park in Lewis County. These swabs were recently analyzed and indicated that four of the bats - two little brown bats
(Myotis lucifugus) and two Yuma myotis (Myotis yumanensis) - had the fungus on them. However, no signs of white-nose
syndrome were observed on any of the bats that were examined in this colony.
Bats use this roosting area in spring and summer but it is unknown where these bats hibernate during winter months.
Detection of the fungal spores in this roosting area is especially important to scientists tracking the disease as it
is the first confirmed detection of the fungus in Washington outside of King County, indicating the pathogen is more
widespread and may be spreading.
Read our blog post
on whitenosesyndrome.org for more details.
Researcher swabs a bat's wing to collect a sample to test for the presence of the fungus that causes white-nose syndrome.
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, Washington's first case of white-nose syndrome was confirmed in a little brown bat (Myotis lucifugus) near
North Bend, 30 miles east of Seattle. 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 North America may be different.
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.
Normal wing of little brown bat.
Photo: Greg Falxa, WDFW
Little brown bat with skin infection on wing.
Photo: Progressive Animal Welfare Society (PAWS)
The fungus that causes white-nose syndrome is harmful to bats but not humans, livestock, or pets. It 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.
Even though the fungus is believed to be primarily transferred from bat-to-bat or bat-to-environment contact, the fungus can
be inadvertently spread by humans. People can carry fungal spores on clothing, shoes, or recreation equipment that has come in
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.
- White-nose syndrome: A little brown bat was found alive on a trail by a hiker in Olallie State Park. The bat was
taken to the Progressive Animal Welfare Society (PAWS) where it later died. The veterinarian noticed clinical signs
of white-nose syndrome including dehydrated, wrinkled wings. After testing the bat at the National Wildlife Health
Center, scientists confirmed it had white-nose syndrome.
- Fungus: A silver-haired bat (Lasionycteris noctivagans) was found in a Seattle park and was taken to a local
Department of Health office due to the potential of rabies exposure to a hiker. The bat tested negative for rabies,
but positive for the fungus.
- Fungus: Researchers collected guano (bat feces) from under a bridge near North Bend in King County. The bridge is
an occasional day roosting spot for bats, but mainly an area where bats forage at night. The fungus was detected in
guano in July 2016, and guano tested positive again during the summer of 2017.
- White-nose syndrome: A Yuma myotis and either a little brown bat or Yuma myotis (species was not genetically
identified) were found on separate occasions near North Bend in King County. Both bats were dead when a biologist
collected them and showed signs of white-nose syndrome. Using a UV light, a WDFW biologist found some areas that
shined a distinctive orange color, one way that researchers can detect possible white-nose syndrome infections. Lab
tests confirmed that these bats had white-nose syndrome.
- Fungus: Guano collected from a maternity roost near North Bend tested positive for the fungus.
- Fungus: Researchers collected swab samples from live bats at a roosting site at Mount Rainier National Park in
Lewis County. Lab results in February 2018 showed four bats tested positive for the fungus, two little brown bats and two
Yuma myotis (species confirmed by acoustic calls).
- White-nose syndrome: A little brown bat or Yuma myotis (species not genetically identified) was found floating
alive in Lake Union near Seattle. The bat was sent to PAWS but died immediately and showed clinical signs of white-nose
syndrome under a UV light test. Lab tests confirmed that this bat had white-nose syndrome.
- White-nose syndrome: A little brown bat or Yuma myotis (species not genetically identified) was found near North
Bend in King County, in the same location as the bats confirmed with white-nose syndrome in April 2017. This bat
showed clinical signs of white-nose syndrome under a UV light test. Lab tests confirmed that this bat had white-nose
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.
- 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 act as
carriers of the fungus to new sites.
- Get involved in bat conservation! Help improve bat habitats be 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, visit our Living With Wildlife - Bats website.