Two Colorado bats found with white-nose syndrome; disease could have 'devastating' impact

Colorado’s first recorded case of white-nose syndrome, a destructive, fungus-caused wildlife disease that has killed millions of North American bats since it was first documented in the United States nearly two decades ago, was identified in La Junta in March 2023.

Less than a year later, Colorado Parks and Wildlife discovered two more infected bats of a different species a distance of more than 200 miles away.

“While it is unfortunate to discover this deadly disease in a second Colorado bat species, CPW did anticipate that this would happen based on what has been documented in other states,” Dan Neubaum, CPW species conservation program manager, said in a news release. “We will continue to monitor the spread of this disease with our partners and ask the public to report sick or dead bats to CPW, particularly when found during winter and spring months.”

Discovery marks three infected bats of two species in Colorado

A "little brown bat” infected with white-nose syndrome was recently discovered in Longmont, Colorado, according to CPW's March 25 release.

The bat was found crawling on a public bike path on Feb. 29. A wildlife rehabber collected it and determined it was dehydrated. The bat’s wings appeared brittle and prevented it from flying, according to the release.

CPW investigated the matter and biological samples were sent to Colorado State University for testing. The tests confirmed the presence of white-nose syndrome.

Two weeks later in Boulder, a second little brown bat was confirmed to have the disease, “indicating that additional bats have been exposed and may be found in the coming weeks,” CPW stated in the release.

The invasive fungus that causes white-nose syndrome has been confirmed in three little brown bat summer roosts in Colorado, but no bats of that species sick with white-nose syndrome were detected in Colorado until earlier this month.

White-nose syndrome was first discovered in Colorado in March 2023 in a Yuma bat collected by National Park Service staff at Bent’s Old Fort near La Junta — just over 70 miles southeast of Pueblo.

The white-nose fungus has been found in other locations in Colorado, but the little brown bats discovered earlier this month are only the second and third bats discovered with clinical signs of the disease in the Centennial State.

The fungus that causes the disease is mainly transported from bat to bat, “making it impossible to stop its spread in the wild,” according to CPW.

“We continue to ask those visiting caves to decontaminate their gear to prevent human spread of the fungus and remind the public not to handle bats when encountered but instead report them to CPW, wildlife rehabbers, or the Colorado Department of Public Health and Environment,” Nebaum said in the release.

What to know about white-nose syndrome

White-nose syndrome was first documented in New York in 2006. Since then, it has been confirmed in 12 North American bat species, and it now occurs in 40 states and eight Canadian provinces, according to CPW.

According to the National Park Service, researchers call the disease “white-nose syndrome” because of the visible white fungal growth on infected bats’ muzzles and wings.

The fungus that causes the disease, Pseudogymnoascus destructans, is a “cold-loving fungus” that infects bats during hibernation, when the flying mammals reduce their metabolic rate and lower their body temperature to save energy over winter. Hibernating bats affected by the disease wake up to warm temperatures more frequently, which results in them using up fat reserves and starving before spring arrives.

How might bat population decline impact Colorado?

According to CPW, the disease’s impact on Colorado “could be devastating.”

Of the 19 bat species native to Colorado, at least 13 may be susceptible to the disease and any large-scale loss of bats could “cause trouble for the health of Colorado’s ecosystems and economy, given estimates that these voracious insect eaters contribute $3 billion annually to the U.S. agricultural economy through pest control,” CPW stated in the release.

Bats play an important role in maintaining Colorado ecosystems, as they can be found in every habitat in the state.

“Not only do they pollinate plants and crops, but all of our bats also eat insects and help control our insect populations,” CPW states on its guide to Colorado bats on its website. “The little brown bat has been known to catch and eat more than 150 mosquitoes and crop pests in less than 15 minutes."

Can white-nose syndrome be passed to humans?

Fortunately, the fungus doesn’t infect humans or pets. According to the NPS, "studies have shown that the fungus grows only at cold temperatures (41-68 degrees F) that are much lower than that of the human body," and no human infections "have ever been documented after exposure to WNS-infected bats or caves."

Bats are the primary way the fungus spreads, according to CPW. However, the fungus can be transported on gear and clothing that has been in contact with contaminated environments, such as caves where bats hibernate.

With that in mind, agencies in Colorado and throughout the U.S. ask that outdoors enthusiasts help contain the spread of the fungus and disease by following these recommendations:

• Stay out of closed caves and mines.

• Decontaminate footwear and all caving gear before and after visiting or touring caves and other places where bats live.

• Do not touch bats. Report dead or sick ones to CPW by calling 303-291-7771 or email wildlife.batline@state.co.us.

• Gear and clothing used in areas where the fungus or WNS occurs should not be used in areas where the fungus is not known to occur.

• To avoid accidentally transporting bats, check canopies, umbrellas, and other outdoor items for bats that may have roosted in nooks or crannies.

Chieftain Editor Zach Hillstrom can be reached at zhillstrom@gannett.com or on X, formerly Twitter, at @ZachHillstrom. Support local news, subscribe to the Pueblo Chieftain at subscribe.chieftain.com.

This article originally appeared on The Pueblo Chieftain: What to know about white-nose syndrome found in bats in Colorado