White-Nose Syndrome Confirmed in Seven Colorado Bat Species

Colorado’s bat populations are facing another difficult chapter.

According to Colorado Parks and Wildlife, white-nose syndrome has now been confirmed in seven of the state’s bat species across ten counties, with the fungus that causes it detected in two additional species and five more counties. Speaking to Rocky Mountain PBS this summer, CPW species conservation program manager Dan Neubaum said the disease is now considered to be moving among Front Range bat populations and is likely working its way up into the mountains along the corridors bats use to travel.

While the news sounds alarming, it should be put into perspective. White-nose syndrome does not infect humans, but it does threaten the bats that quietly provide one of nature’s most valuable services: controlling insect populations across Colorado every night.

For years, Get Bats Out has been helping Colorado homeowners and businesses solve bat problems through humane exclusion. Reports like these are a reminder that protecting homes and protecting bats aren’t competing goals. They’re closely connected.

A Deadly Disease Continues to Spread

White-nose syndrome (WNS) is caused by Pseudogymnoascus destructans, a cold-loving fungus that infects bats while they hibernate during the winter.

The disease gets its name from the white fungal growth that often appears on an infected bat’s nose, ears, and wings. But the real danger isn’t what you can see. CPW explains that the fungus thrives in the same cold temperature range found in bat hibernacula, and that hibernating bats have suppressed immune systems that leave them vulnerable to infection. Infected bats arouse from hibernation more frequently than they should, burning through the fat stores they need to survive until spring.

Instead of conserving energy through the winter, they wake repeatedly, become dehydrated, and often die of starvation before insects return.

Since white-nose syndrome was first documented in New York in 2006, it has killed millions of bats across North America. The Center for Biological Diversity puts the toll at roughly 6.7 million. A 2021 study found that three bat species, including the little brown bat found in Colorado, declined by more than 90% within seven years of being exposed, making white-nose syndrome one of the deadliest wildlife diseases ever recorded.

Colorado’s own timeline is short but moving quickly. The fungus was confirmed in the state in the summer of 2022. The first Colorado bat to die from the disease was a Yuma myotis, found at Bent’s Old Fort National Historic Site in the spring of 2023. Both the fungus and the disease have since been confirmed in additional counties and species.

Why Wildlife Experts Are Concerned

For biologists, the expanding county and species lists are a sign that white-nose syndrome is establishing itself in areas where healthy bat populations are essential to local ecosystems.

CPW reports that roughly 20 bat species live in Colorado, some year-round and some passing through during migration. The species now confirmed with white-nose syndrome include the big brown bat, little brown myotis, fringed myotis, long-legged myotis, western long-eared myotis, western small-footed bat, and Yuma myotis. The fungus alone has also turned up on Mexican free-tailed bats and Townsend’s big-eared bats.

Many of Colorado’s bats spend their summers feeding on mosquitoes, moths, beetles, and other night-flying insects before hibernating through the winter in caves, mines, and rock crevices. Those same hibernation sites provide the cold, humid conditions where the fungus thrives.

Researchers are continuing to monitor which species are hit hardest and how populations respond over time. Not every species is equally vulnerable, but the disease has already demonstrated how quickly it can reshape bat populations across an entire region.

Colorado’s Bats Do More Than Most People Realize

Bats often get attention only when one finds its way into an attic. The reality is that they’re among Colorado’s most beneficial native mammals.

The U.S. Forest Service reports that a single little brown bat can catch 1,000 mosquito-sized insects in an hour, and that a nursing mother eats approximately 4,500 insects every night. CPW notes that little brown bats have been recorded eating more than 150 mosquitoes and crop pests in under 15 minutes. Now imagine the impact an entire colony has across Colorado’s warmer months. That appetite naturally reduces mosquitoes and agricultural pests, benefiting homeowners, farmers, and the environment alike.

Without healthy bat populations, insect numbers can climb, putting more pressure on crops and potentially increasing the need for chemical pest control. It’s easy to overlook these contributions because bats do their work after dark, but every summer evening they provide an ecological service that’s difficult to replace.

Recovery Won’t Happen Overnight

One reason white-nose syndrome is so concerning is that bats reproduce very slowly. Unlike many small mammals, most bat species give birth to only one pup each year, so recovering from large population losses can take decades even under ideal conditions. Every healthy colony matters.

Colorado is still in the early stages of understanding how the disease will affect its native bats, but the state isn’t starting from scratch. Nearly two decades of research in eastern states gives Colorado biologists a foundation to build on, and CPW is currently conducting vaccination trials to see whether proactive measures can protect bats before populations crash.

Scientists are still searching for treatments and management strategies, and there is no simple solution capable of stopping white-nose syndrome across the continent. Conservation will likely depend on continued research, habitat protection, and responsible human interactions with bat populations.

Does White-Nose Syndrome Affect People?

White-nose syndrome is not a human disease. The fungus affects bats during hibernation and has not been shown to infect people, pets, or livestock.

That said, homeowners should never handle bats themselves. Like any wild mammal, bats can carry rabies, though CPW notes that studies suggest fewer than 1 percent of bats are infected. Because bat bites can be difficult to detect, any direct contact with a bat should be treated as a possible exposure and reported to your local public health official.

Bat droppings (guano) can also become a health concern when they accumulate inside attics or wall voids. Large accumulations may support the growth of fungi associated with histoplasmosis, which makes proper cleanup an essential part of any professional bat exclusion project.

White-nose syndrome and histoplasmosis are entirely separate issues, but both reinforce the importance of treating bat situations with care and relying on trained professionals when bats enter a structure.

Why Humane Bat Exclusion Matters More Than Ever

As Colorado’s bat populations face increasing pressure from white-nose syndrome, the way bats are removed from buildings matters more than it used to.

Bats don’t belong inside homes or commercial buildings, but they remain an important part of Colorado’s ecosystem. Professional exclusion resolves that tension. Rather than trapping or poisoning bats, exclusion allows them to leave a structure safely before every entry point is permanently sealed. The bats return to their natural habitat while homeowners gain lasting protection against future infestations.

Timing is part of the work. CPW specifically warns against sealing bats out during pupping season, both because it can kill flightless young and because trapped adults tend to end up inside living spaces as they search for a way out. A professional inspection determines the safest and most effective time to complete the job while protecting both the property and the colony.

Responsible exclusion isn’t just good for homeowners. It’s good for Colorado’s wildlife as well.

What This Means for Colorado Property Owners

The continued spread of white-nose syndrome doesn’t change what homeowners should do when bats move into an attic, garage, barn, or commercial building. It does raise the stakes on choosing the right solution.

If you suspect bats are living on your property:

• Avoid sealing entry points until it’s confirmed the bats have safely left.
• Never rely on poisons or chemical repellents, which are ineffective and can create additional problems.
• Don’t attempt to remove a colony on your own.
• Schedule a professional inspection to identify how the bats are entering and determine the best time for humane exclusion.

If you find a grounded, lethargic, or dead bat between December and June, CPW asks the public to report it as part of white-nose syndrome surveillance. The agency maintains a dedicated line at 303-291-7771. Do not pick the bat up. Placing a box or container over it is enough to prevent further disturbance until it can be collected.

Every building presents unique challenges, and every colony behaves differently depending on the season. A thorough inspection is the first step toward a permanent solution that protects both your property and Colorado’s native bats.

Protecting Homes While Protecting Colorado’s Wildlife

The spread of white-nose syndrome through Colorado’s bat species is a reminder that these animals face challenges far beyond the homes and buildings they occasionally enter.

White-nose syndrome, habitat changes, and other environmental pressures continue to affect bat populations across North America, which is why responsible bat management has never been more important. At Get Bats Out, we believe property owners shouldn’t have to choose between protecting their property and protecting wildlife.

Humane bat exclusion allows both. By safely removing bats, permanently sealing their entry points, and respecting seasonal timing, homeowners can resolve bat problems while supporting the long-term conservation of one of Colorado’s most valuable native species.

As scientists continue studying white-nose syndrome, one thing remains clear: bats deserve our respect, our protection, and a safe place to live, just not inside our homes.

If you’re dealing with bats in a Colorado home or commercial building, schedule an inspection with Get Bats Out or call us to discuss your situation. We handle humane exclusion, permanent sealing, and guano cleanup, with timing planned around the health of the colony.

Your Local Bat Removal Specialist,

Michael Koski | Owner & President | Get Bats Out

Sources

• Colorado Parks and Wildlife, Living with Bats (species counts, confirmed WNS species and counties, timeline, pupping season guidance, rabies statistics, reporting line): https://cpw.state.co.us/living-bats
• Rocky Mountain PBS, A devastating bat disease continues to spread in Colorado (Neubaum on Front Range spread): https://www.rmpbs.org/news/science-environment/white-nose-syndrome-bats-colorado.
• National Park Service, First Colorado Bat Tests Positive for White-nose Syndrome (2023 Yuma myotis): https://www.nps.gov/beol/learn/news/first-colorado-bat-tests-positive-for-white-nose-syndrome.htm
• U.S. Forest Service, It’s bat time (4,500 insects per night): https://www.fs.usda.gov/about-agency/features/its-bat-time
• The Colorado Sun (2021 study on 90%+ declines; Center for Biological Diversity mortality figure): https://coloradosun.com/2024/04/15/colorado-bats-white-nose-syndrome/
• WhiteNoseSyndrome.org (national response and decontamination guidance): https://www.whitenosesyndrome.org/