Fungus deadly to bats found in Colorado's Rocky Mountain National Park, crosses Continental Divide

CBS News

15-05-2025

A deadly fungal disease impacting bat populations has now been detected west of the Continental Divide in Colorado for the first time, raising concerns among wildlife officials. While Colorado has already identified White Nose Syndrome in Colorado in different parts of the state, the detection of the fungus Pseudogymnoascus destructans in bat guano at the Holzwarth Historic Site on the west side of the Rocky Mountain National Park adds to the growing concern for bat populations.
"It means that the fungus is continuing to spread throughout Colorado," Michelle Verant Wildlife Veterinarian with the National Parks Service, explained. "All previous cases in the state were on the eastern part... this is the first detection of the fungus West of the Continental Divide in Grand County, Colorado."
National Park Service
White-Nose Syndrome thrives in the cold temperatures where bats hibernate. The fungus grows on their skin, particularly their wings and face, causing damage that often leads to death before the bats can emerge from hibernation in the spring.
Verant explained that bats play a crucial role in maintaining healthy ecosystems, eating insects by the thousands each night, helping to control pests like mosquitoes, moths, beetles, and crickets – some of which are significant agricultural threats. According to a study, the economic impact of bats is also significant. Studies estimate that bats provide $3 billion to $22 billion each year in pest control services to North American farmers.
While WNS has caused massive population collapses on the east coast, to the tune of 90% in some cases, according to Verant, Colorado has yet to see that kind of devastation. That doesn't mean scientists are not actively monitoring Colorado bats for a crisis just like that, now that Pd is in the state. A small glimmer of hope comes from the idea that western bat species may have natural defenses against the spread of the fungus.
"Western bats tend to hibernate in more dispersed locations like rocky outcrops and crevices, unlike the large colonies found in eastern caves and mines," said Verant. This difference in hibernation habits could potentially slow the spread of the fungus, as fewer bats are bumping into each other, with a chance to spread WNS.
However, Verant cautions that in many cases, once the fungus arrives, severe disease and death follow within a few years.
Since Colorado is home to multiple bat species, each with unique behaviors, Verant said understanding how the disease affects each species is critical. Those differences could also lead to an unexpected defense. In the meantime, humanity is still working to create a solution to stop the spread of the fungus, with researchers focusing efforts on developing tools to help bats survive the disease, including antifungal compounds, environmental sprays, and even a vaccine that can boost bat immune systems.
"It's really depressing to see such a dramatic loss of these fascinating and valuable creatures," Verant said. "It will be important to continue monitoring this colony to understand if and when bats develop disease and suffer impacts from that."
If you find a dead or injured bat, do not handle it. Please report it to Colorado Parks and Wildlife at 303-291-7771 or email [e-mail].