More topics

White-Nose Syndrome (WNS)

Last updated on May 12, 2026

White-nose syndrome (WNS) is a disease with rapid spread. It can cause high levels of mortality in bat populations. It is caused by an invasive fungus called Pseudogymnoascus destructans (Pd).

On this page

About White-Nose Syndrome (WNS)

Since the winter of 2006, WNS has killed over six million bats in eastern North America. In 2016, WNS was discovered in Washington State and has continued to spread. There have been no cases of WNS detected in B.C.

Bats infected with WNS may:

  • Develop symptoms during the hibernation period. This includes a white fungus on their nose and wing membranes (fungus is not always visible on infected bats, particularly outside of the hibernation period)
  • Wake from hibernation to groom off the fungus, using up limited energy reserves
  • Fly in daylight in winter to find water or food
  • Die from lack of energy in winter or early spring

Please report any dead bats or unusual bat activity.

WNS impacts on bat colonies

WNS can be devastating to affected bat colonies. Mortality (death) rates in some cases are 80% to 100%. For example, in 2014 the Little Brown and Northern Bats species were emergency listed under the federal Species at Risk Act. Due to their population declines in eastern North America. 

Bats provide billions of dollars in pest control services in North America each year. Bats are major predators of invertebrates and help to control:

  • Forests
  • Agriculture
  • Urban pests

For example, endangered Little Brown Bats can eat 600 mosquitoes per hour.

Preventing the spread of WNS

Humans can accidentally carry and spread the fungus that causes WNS. Decontamination protocols for clothing and equipment that have been used in bat habitats, such as caves and mines, are available below. Anyone conducting work around bats or in bat habitats should follow these protocols. 

B.C. has areas designated as high-risk for Pd and WNS (PDF, 2.4MB). Gear and equipment used in or near caves, bat roosts or bat guano must not be moved from a high-risk zone to a low-risk zone (link to decon protocol). Using dedicated equipment within each zone is the best way to prevent accidental spread of Pd spores.

Long-distance transport vessels can carry infected bats into new areas. These vessels include:

  • Semi-trucks
  • RV campers
  • Truck trailers
  • Cargo ships

It is important to close potential bat roosting sites at night, such as:

  • Cargo hatches
  • Trailers
  • Storage cabinets
  • Tent awnings
  • Umbrellas

Make sure to check for bats in the corners and crevices of cargo holds and trailers before leaving the site.

Contact information

For all wildlife health inquiries or reports, contact BC Wildlife Health:

Wildlife Health Office
250 751-7246
Email
WildlifeHealth@gov.bc.ca