NEWS RELEASE
Feb. 13, 2025
SIERRA VISTA, Ariz. – An Arizona bat has tested positive for Pseudogymnoascus destructans (Pd), the fungus that causes the deadly white-nose syndrome (WNS) disease in bats.
The bat, a cave myotis (Myotis velifer), was sampled by biologists conducting surveillance at Fort Huachuca near Sierra Vista in June 2024. The bat exhibited suspicious wing abnormalities that may be related to the disease. During the surveillance effort, four additional bats, including two other species, were determined to have trace levels of the fungus, indicating that Pd is present in the area.
“The Fort has been monitoring for Pd since 2014 using visual diagnostic methods and initiated sampling for Pd DNA in 2017,” said Debbie Brewer, Fort Huachuca wildlife biologist. “We were put on alert in 2021 and 2023 with the low-level Pd detections. Though not unexpected, our 2024 high-level positive detection in cave myotis is highly concerning and should put other land managers in the Southwest on alert that habitat protections for this and other species of bat are warranted.”
WNS is named for the fuzzy white growth of fungus observed on infected bats. Cave myotis are especially vulnerable to WNS because they hibernate in cold caves with high relative humidity which is optimal for fungal growth, but any hibernating bat could be susceptible to the disease. Since its discovery in 2006, WNS has spread to 40 states and 9 Canadian provinces and killed millions of bats nationwide. WNS does not pose a risk to the public or pets. Although bats themselves are the primary way the fungus spreads, human activity in caves is also a major concern as fungal spores may be inadvertently carried into caves on clothing and equipment.
“It’s concerning, but not surprising given how Pd has been spreading from state to state over the past several years,” said Angie McIntire, state bat specialist, Arizona Game and Fish Department (AZGFD). “This disease did not exist when I first began working with bats. To see new threats to our bat populations like this is disturbing.”
Now that Pd has been confirmed in Arizona, the AZGFD asks the public to help monitor the arrival of white-nose syndrome in bats statewide. Bats infected with WNS may display unusual behavior, which generally looks like a bat that is unable to fly, or is on the ground or low on a wall. Do not handle live bats. Report bat observations or sick, injured or dead bats to bats@azgfd.gov. Include location, contact information and a photo, if possible, along with any other useful information.
AZGFD along with agency partners and researchers have been conducting surveillance for WNS for more than 10 years. Samples from those efforts are examined by the Pathogen and Microbiome Institute at Northern Arizona University to assess whether Pd is present.
Since 2019, trace amounts of Pd have been detected during surveillance efforts in at least 4 counties (Mohave, Coconino, Yavapai, Cochise) across Arizona. In 2019, a trace amount of fungus was found on a fringed myotis (Myotis thysanodes) at Grand Canyon National Park. Between 2021 and 2024, surveillance efforts found trace amounts of the fungus on 8 bats, including cave myotis, southwestern myotis, and big brown bats.
Arizona is home to 29 bat species, about half of which are known to hibernate during the winter, making them vulnerable to WNS. WNS has previously been discovered in New Mexico and Texas, where it is impacting cave myotis, a western species that may be particularly susceptible to the disease in the Southwest.
For additional information about white-nose syndrome in bats, visit https://www.whitenosesyndrome.org/.