A Night Surveilling Bats for White-Nose Syndrome in the Klamath Region

Bats come in many shapes and sizes, and all play a critical role in their environments. Some pollinate crops such as agave; some spread the seeds of fruits like figs; insect-eating bats control pests that harm farms. Rainforests, deserts, deciduous forests and other biomes depend on them. Now many species face a major threat: white-nose syndrome (WNS).

The threat

• WNS reached North American bats in 2006.
• It is caused by the fungus Pseudogymnoascus destructans (Pd), which thrives in caves, and it endangers hibernating bats by disrupting hibernation, leading to starvation and death.
• It has hit eastern North American bats hard, and there is still no effective treatment. Losing these bats could have serious consequences for ecosystems and people.

In southern Oregon and northern California, the NPS Klamath Network is part of a multiagency effort against WNS, starting with surveillance to learn where the fungus is spreading in the West.

A night with the crew

One May evening, a crew of six set up at the Klamath Fish Hatchery, just north of Upper Klamath Lake in Oregon.

• The Oregon Department of Fish and Wildlife has put more than 20 bat boxes around the hatchery, probably home to thousands of Yuma myotis (Myotis yumanensis), a common southern Oregon bat.
• Before dusk, the crew shone a light into one box and found 80–150 bats inside.
• They fitted a funnel-shaped plastic sheet to the box's opening, ending in a sweep net.
• After dusk, bats flew out and slid into the net. The crew removed it and placed each bat in a small, breathable drawstring bag.

The goal is at least 25 bats a night; this night brought in well over 25. Each bat was then examined:

1. Ultraviolet light on the wings — lesions from the Pd fungus glow orange.
2. A check for other signs — scarring, holes in the wing, or white fungal growth.
3. A swab to test for Pd.
4. Release into the night.

One otherwise healthy female Yuma myotis had a large tear in her wing, which the crew measured and recorded.

Why Myotis

The team focuses on the genus Myotis, because most of its species are susceptible to WNS, and mainly on the little brown bat (Myotis lucifugus) and Yuma myotis, which roost in colonies, making it possible to catch enough bats. Bats ignore boundaries, so the team goes wherever they live — buildings, bridges or bat boxes, on state, federal or private land.

Protecting bats

• Surveillance is one of many ongoing efforts. Researchers are testing a WNS vaccine, and studying whether a specific wavelength of ultraviolet light, UVC, can kill the fungus with little harm to cave environments.
• People matter too. Cavers can unknowingly carry the fungus between caves. Ideally, don't use the same shoes, clothing or gear in different cave systems; if you must, decontaminate them first.
• Public awareness of white-nose syndrome is essential to protecting these animals.

Sources

Based on "Hands-On Bat Conservation," by Emily Heller, science writing intern, NPS Klamath Inventory and Monitoring Network, adapted from The Klamath Kaleidoscope newsletter (Fall–Winter 2024) by Sonya Daw, National Park Service; rewritten in hubnx's own words.