It’s a dark night, and the illumination comes only in beams from headlamps worn by a dozen or so scientists, students, researchers, and volunteers waiting for tiny bats to emerge from their slumber. They are at Northwest Trek Wildlife Park, home to a large wild bat colony.
The goal tonight is to capture 50 bats to further their work toward helping bats survive white-nose syndrome. This bat fungal disease has killed millions of hibernating bats in Eastern North America. It was first detected in Washington state in 2016.
The collaboration between Northwest Trek Wildlife Park and other partners is one of optimism. The researchers hope an innovative probiotic spray will help bats survive white-nose syndrome.
According to the Washington Department of Fish and Wildlife, if the spray proves effective, it could be “revolutionary” in saving bats in the Pacific Northwest and beyond. Other major partners in the research study are Wildlife Conservation Society Canada, McMaster University, Thompson Rivers University, and Woodland Park Zoo.
“We love wild bats at Northwest Trek, and we’re excited to participate in this important research study every year to give them the best chance of survival,” said Rachael Mueller, the wildlife park’s conservation program coordinator.
The disease only affects hibernating bats and does not threaten humans or other wildlife. Healthy bat populations are essential for the entire ecosystem because bats eat mosquitoes, moths, and other insects.
The group started installing a harp trap made of framing and long nylon strands. When the bats leave their maternity roost, they enter the harp trap and gently fall into a clear bag below. A researcher on a ladder scooped them up individually to be examined.
They were each placed in cloth bags with long ties on top that were knotted and then hung inside the perimeter of two orange buckets customized with notches to grasp the strings and hold the bats—a bat waiting room, so to speak.
Then, they gave each bat-filled bag a little shake in front of an EchoMeter to measure the frequency of its call. Each bat species has a unique echolocation frequency. The bats were identified as either little brown bats or Yuma myotis. They look similar, but their frequencies helped tell them apart in real-time.
Next, the bats were closely and carefully examined. The biologists and rabies-vaccinated helpers, wearing headlamps, masks, gloves, and protective outer gear, handled each delicate bat with loving care.
The biologists then weighed them by placing the bat-filled bag into an empty coffee cup on a tiny scale. They took their measurements, microbiome samples, and reproductive information. They then carefully outstretched their tiny wings (that look and feel a bit like nylons) to look for signs of white-nose syndrome, using a handheld ultraviolet light to detect orange fluorescence associated with the disease.
Bats that had not previously been microchipped had theirs implanted under their skin, and they were all set free to continue their nightly ritual of intensive bug-eating.
Mueller said there still is a lot to learn about white-nose syndrome and bats in general. For example, a fungus called Pseudogymnoascus destructans, commonly referred to as Pd, causes white-nose syndrome in bats, but not all bats that have the fungus on them become sick with the disease. Several species of bats have been found with the fungus but have not been affected—yet another mystery. Out east, the outbreaks hit harder than here in the west.
Everyone hopes the probiotic spray, which contains naturally occurring “good bacteria,” protects the bats by inhibiting the growth of the fungus that causes white-nose syndrome.
Bats affected by white-nose syndrome wake more frequently during the winter, causing them to burn through their fat reserves needed to survive hibernation.
During the multi-year study, researchers sprayed powdered clay containing the probiotics into the bat roosts at three other sites in Washington. The dust gets on their bodies and wings when they go inside.
Only time and continuing research will tell if it’s working. More long nights will be ahead for some very passionate people who care a lot about these often misunderstood fuzzy flying mammals that contribute so much to a healthy ecosystem.