Note: See previous blog, "White-nose syndrome marches westward: scientists and others work to save bats" for information on initial detection of white-nose syndrome in Washington.
Tracking down a deadly bat disease called white-nose syndrome (WNS) in Washington is a tough job, and in many ways, we are working blind. We don’t know where most of our 15 bat species spend their winters, and many of the tools and techniques that scientists use to detect WNS are designed to be used in places where bats hibernate.
The Washington Department of Fish and Wildlife (WDFW) is working with partners to figure out how to detect and prevent the spread of WNS in Washington bats. Meanwhile, scientists and biologists are working to develop more advanced disease surveillance and population monitoring techniques that will be able to better detect the disease in bats in western North America.
You can help – If you find a sick or dead bat in Washington, or notice bats unable to fly, please report your observation to WDFW.
Another bat confirmed with WNS in Washington
In mid-April 2017, Happy Valley Bats, a local rehab facility that specializes in rescuing bats, received a call about a bat unable to fly near North Bend in King County. WDFW biologist Chris Anderson responded and located the bat, which had died before he arrived. When Chris collected and examined the bat, he noted some signs that are common in bats with WNS. Rather than being soft and flexible, the bat’s wing membranes were sticky. Using a UV light, Chris found some areas that shined a distinctive orange color, one way that scientists and biologists can detect possible WNS infections.
Chris shipped the bat to the USGS National Wildlife Health Center (NWHC) for testing. NWHC scientists tested the bat’s wing which showed the fungus was present, and additional tests confirmed the bat had WNS. Because several species of bats in the genus “Myotis” live in Washington, NWHC scientists conducted additional tests to determine the bat species based on its DNA. The bat species was confirmed to be Yuma myotis (Myotis yumanensis), a common bat found in Washington.
Finding the fungus that causes WNS
One of WDFW’s partners, Bat Conservation International, surveyed and collected samples from several Washington areas where bats might hibernate. Very few of these area contained bats, but environmental samples from one site in western Washington returned a very weak positive result for Pseudogymnoascus destructans, the fungus that causes WNS. This suggests that the fungus might be present in low amounts, but researchers need to do additional testing to be certain.
This time of year, many bats are emerging from hibernation, and there are a few ways we might detect the fungus in spring months. By trapping bats early as they return to summer roosting areas, and collecting wing swabs and fresh guano (bat feces), we may be able to determine if they were exposed to the fungus. Although this doesn’t help us identify where the bats may have come in contact with the fungus, it helps us better understand if bats in other Washington locations have also been exposed.
This information can help wildlife managers determine how to best focus resources to look for places where bats might hibernate or congregate. Because the fungus can survive in the environment for an indefinite period of time, collecting sediment and guano samples in places where bats might visit helps us better understand the fungus distribution.
It is possible that winter hibernating areas could serve as reservoirs for the fungus. Bats that stop in to these hibernating spots, even if just for a short time, could deposit or pick up the fungus and move it to other areas where bats may 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 piece of the puzzle.
How you can help
Each time a new clue is revealed, it helps scientists and biologists get one step closer to understanding how WNS might affect our western bat populations. You can help us track this deadly disease. Reports of sick or dead bats, as well as reports of places where groups of bats may be “hanging out”, is key to the success of tracking WNS and working toward conserving our bats.
Please visit the Washington Department of Fish and Wildlife page for more information about bats in WNS in Washington, or to report bats: http://wdfw.wa.gov/conservation/health/wns/