Article

Hands-On Bat Conservation

Small brown bat being held by gloved hand. — A female Yuma myotis bat comfortably perched on a bat crew member’s hand during a bat survey at the Klamath Fish Hatchery.
NPS / Alice Chung-MacCoubrey

Article by Emily Heller, Southern Oregon University Science Writing Intern for the Klamath Inventory and Monitoring Network

Bats come in many shapes and sizes, but they all have one thing in common: they play a critical role in their environment. Some species are pollinators, aiding in the fertilization of crops such as agave, while others help disperse the seeds of fruits they eat, like figs. Insectivorous bats help control pest populations, benefiting agriculture. Whether they are insectivores or pollinators or seed dispersers, they are indispensable to the healthy functioning of rainforests, deserts, deciduous forests, and other biomes. However, a major threat has emerged that endangers many bat species: white-nose syndrome (WNS).

In 2006, WNS arrived in North American bat populations. Caused by the fungus Pseudogymnoascus destructans (Pd), which thrives in cave environments, WNS poses a serious threat to hibernating bats. The disease disrupts bats’ hibernation cycles, leading to starvation and death. Since its discovery, WNS has significantly affected eastern North American bats, with no effective treatment yet. The loss of these bat populations could have severe ecological consequences, impacting humans and the environment.

In southern Oregon and northern California, the NPS Klamath Network is part of a multiagency effort to do something about this threat. The first step is finding out where the fungus is spreading in the West through surveillance. I joined the network’s bat crew in May to watch surveillance in action.

Photo collage of house with two wooden, hollow boxes on the exterior and photo of flashlight beam shining into the bottom of one of the boxes. — Top: bat boxes on the side of a building at the Klamath Fish Hatchery. Bottom: shining a flashlight into a bat box to check for bats.
Emily Heller

A Night with the Surveillance Crew

Our crew of six people arrived during daylight at the Klamath Fish Hatchery just north of Upper Klamath Lake in Oregon to set up for an evening of trapping and examining bats. In the late afternoon, before dusk, we checked for bats inside the bat boxes installed at the site.

At the Klamath Fish Hatchery, the Oregon Department of Fish and Wildlife provides bats with roosting options by placing boxes throughout their property. Bat boxes provide suitable roosts for southern Oregon bats, such as the common Yuma myotis (Myotis yumanensis). The 20+ bat boxes provide a home for likely thousands of Yuma myotis.

We flashed a light up into one of the bat boxes at the hatchery and found 80–150 bats roosting inside.

Top photo of plastic bag fitted under a bat box and bottom photo of bats inside a net. — Top: adding a plastic funnel that ends in a sweep net to the bat box opening before the bats fly out. Bottom: bats trapped inside the sweep net.
Emily Heller

After confirming that a bat box had bats inside it, the bat team applied a funnel-shaped plastic sheet to the mouth of the box so the bats would slide into the sweep net at the bottom of the plastic.

After dusk, the bats started flying out from the bat box, landing in the net. The bat crew then carefully removed the sweep net from the bat box and examined each individual.

Examining a bat wing with an obvious tear in it. — An otherwise healthy female Yuma myotis bat was found with a large tear in her wing. Bat crew members measured and recorded the size of the tear.
Emily Heller

The bat crew aims to catch at least 25 individual bats, and on this night, this technique caught well over 25. Once the quota of bats had been reached, a team member safely handled the sweep net full of bats and gently placed each individual bat into small, breathable drawstring bags to examine. During the exam, ultraviolet light is aimed at each bat’s wings. Lesions caused by the Pd fungus fluoresce orange under the light. The team also inspects for other signs of Pd, such as scarring, holes in the wing, or the presence of white fungal growth. They then swab the bats to test for Pd. After examination, the bats are released into the night.

The network’s bat team focuses on bats in the genus, Myotis, because most species in this genus are susceptible to white-nose syndrome. The team works primarily with the little brown bat (Myotis lucifugus) and Yuma myotis because these species often roost in colonies, making it possible to capture the required number of bats for surveillance. Bats don’t pay attention to boundaries. Consequently this NPS-based team goes to where the bats are, whether they are living in buildings, bridges, or bat boxes on state, federal, or private property in the Klamath region.

Protecting Bats

Efforts to protect bats from WNS, like these surveillance methods, are ongoing. Researchers are testing a WNS vaccine. Researchers are also studying the potential for a specific wavelength of ultraviolet light—UVC—to kill the Pd fungus with minimal collateral damage to cave environments.

In addition to scientific research, human behavior is critical in preventing the spread of the disease. People who explore caves should take precautions to avoid unintentionally transferring the Pd fungus between cave systems. Ideally, shoes, clothing, and gear used in one cave system should not be used in a different area’s cave system. The next best option is to decontaminate any shoes, clothing, or gear used in one cave system before exploring a different one. Public awareness of white-nose syndrome and bat conservation is essential to safeguarding these vital creatures.