Seventeen bat species roost on Yosemite’s cliffs. As people scale those walls, park scientists are concerned about the potential for climbers to spread white-nose syndrome (WNS), which has killed millions of bats in the eastern U.S. and Washington State.

The fungus that causes WNS thrives in caves like the ones in which Yosemite’s bats roost during the winter. Irritation from the fungus prompts bats to emerge from hibernation, a dangerous disruption that can end in starvation.

In 2019, to determine whether and how Yosemite’s bats are at risk, scientists worked with climbing rangers and climbing stewards to survey 20 climbing routes in Yosemite Valley and Tuolumne Meadows, searching for signs of bat roosts. They also placed data-collection devices at carefully selected locations on the walls to gather details on temperature and humidity, with the goal of identifying potential fungal hotspots. The knowledge gained from their research will inform strategies for preventing WNS from taking hold in the park, such as educating climbers about how to avoid spreading the deadly fungus.

Your gifts supported critical research to help protect the health of Yosemite’s vertical landscape and its wild residents.

Completed in partnership with Yosemite National Park, Devils Tower National Monument, California Department of Fish and Wildlife, and U.S. Fish and Wildlife Service.