Bats

Holding the distinction of being the world’s only mammal capable of self-powered flight, bats perform a nightly airborne ballet that surprises and delights visitors in Rocky Mountain National Park who are lucky enough to spot them. For those out when the sun sets, you may get to see an incredible display of aerial acrobatics performed over lakes and ponds as bats search for flying insects. This can be a magnificent and unique experience set against a breathtaking twilight landscape.

Rocky Mountain National Park is Home to 9 Known Species of Bats:

• Western small-footed myotis (Myotis ciliolabrum)
• Long-eared myotis (Myotis evotis)
• Fringed myotis (Myotis thysanodes)
• Long-legged myotis (Myotis volans)
• Hoary bat (Lasiurus cinereus)
• Silver-haired bat (Lasionycteris noctivagans)
• Big brown bat (Eptesicus fuscus)
• Townsend’s big-eared bat (Corynorhinus townsendii)

While the hoary bat, fringed myotis and Townsend’s big-eared bat have long been suspected to reside in the park, these species were recently identified and confirmed here for the first time as part of on-going bat research in RMNP.

Want to learn more about Bat Research happening in the park? Visit https://www.nps.gov/articles/bat-research-in-rocky-mountain-national-park.htm

What Roles Do Bats Play in the Ecosystem?

Bats have an important role in ecosystems inside Rocky Mountain National Park and across the State of Colorado. They prey on insects like mosquitoes, therefore helping to control insect populations.

Little brown bats, for example, have been known to catch and eat more than 150 mosquitoes and crop pests in less than 15 minutes. Bats also pollinate plants and crops and can help disperse seeds.

Bat Habitat

Bats utilize a diverse range of habitats in RMNP, often near water sources or forest clearings. Bats have been detected using acoustic monitors at elevations ranging from between 7,600 feet to 11,350 feet in a variety of habitats including sagebrush, lodgepole pine, ponderosa pine, spruce-fir, and sub-alpine.

• Fun Fact - Five species of bats have been detected in RMNP in areas above 11,000 feet.

In early summer, female bats congregate in maternity colonies for the duration of their pregnancy (6-9 weeks) and into the first several weeks of their pups' lives. Bats are sensitive during this time and may abandon their young if disturbed.

Maternity colonies have been identified in park buildings and this information prompted the installation of bat boxes near these locations. Bat boxes provide safe roosting environments for maternity colonies and help to mitigate human-bat interactions and human disturbance that can occur when bats roost in buildings.

During winter, it is currently thought that most Rocky Mountain bats hibernate, but little is known about western bat populations’ winter habitats in general.

What Threats Do Bats Face?

Bats face a number of threats, including climate change, habitat loss, and disease.

Changing climate conditions may increase the severity and frequency of extreme weather events, which in turn impact bats’ ability to fly, hunt, migrate, or hibernate safely. As global temperatures change, regions that formerly provided hospitable places for bats to undergo their winter hibernation may begin to shift.

Habitat loss, degradation, and fragmentation can occur as human expansion and development encroach on the habitat that bats rely upon.

Diseases, like white-nose syndrome, have been blamed for millions of bat deaths worldwide. At some sites, fatality rates of up to 90-100% have been reported.

Learn more about threats to bats here: Threats to Bats

White-Nose Syndrome (WNS)

Nationwide, concern about bats has grown due to white-nose syndrome (WNS), which is a fatal disease caused by the fungus Pseudogymnoascus destructans (Pd). This fungus can spread rapidly, primarily through bat-to-bat contact. WNS does not cause illness in humans, but humans are able to spread the fungus to new places.

Pd infection can be most readily observed by the fuzzy white growth this fungus causes on infected bats’ faces and wings. In the early stages of infection, Pd cannot be detected through observation alone.

WNS disrupts the hibernation cycle of affected bats, resulting in starvation, freezing, and death when bats come out of hibernation before normal life-sustaining environmental conditions are met.

WNS has been blamed for millions of bat deaths nationwide since its initial detection in New York State in 2006. The westward spread of this disease has brought WNS uncomfortably close to home. Laboratory tests conducted by the U.S. Geological Survey (USGS) have confirmed that Pd has been positively detected in bats found in the Holzwarth Historic Site area located on the west side of Rocky Mountain National Park. This is the first confirmed detection of Pd in Grand County, Colorado.

In July 2022, the first confirmed case of WNS was reported in Southeastern Colorado. Pd and WNS have also been confirmed in Larimer County, Colorado.

Any new detection of Pd is worrisome because bats are vital for healthy ecosystems. Colorado Parks and Wildlife and the USGS, along with U.S. Fish and Wildlife Service and National Park Service, have been conducting WNS surveys for over a decade, monitoring bats for presence of Pd.

Colorado is home to 19 native bat species, at least 13 of which may be susceptible to this disease. Colorado's native bats are all insect eaters and use various habitat types across the state. They are most active during the summer months and spend the winter either hibernating in underground roosts throughout the state or migrating south. The National Park Service and other state and federal agencies will continue to monitor bats throughout Colorado.

To learn more about WNS and how it impacts bats, visit https://www.whitenosesyndrome.org/

Bats, Rabies, and You

In a healthy colony, typically less than 1% of bats are sick with rabies, which they can transmit to humans through saliva in a bite or scratch. Raccoons, skunks, and foxes are other important reservoirs of rabies in the US. All animals with rabies will die from the disease.

Rabies is fatal in humans, but is 100% preventable with proper medical care following an exposure.

Each year in the U.S., up to 30,000 persons receive rabies vaccination due to potential exposure to a rabid animal, including bats. Unfortunately, each year 3-5 people die of rabies in the U.S. due to lack of timely and appropriate medical care.

Follow These Tips to Avoid Exposure to Rabies:

• Watch wildlife from a safe distance.
• Tell a ranger if you see an animal acting strangely.
• Pets are also at risk of rabies, so keep them away from wildlife and be sure to keep vaccinations up-to-date.
• Tell children about rabies—they’re most at risk!

To learn more about the health of humans, animals, and the environment, visit the National Park Service's One Health page.

To learn more about rabies in the State of Colorado, visit the "Bats and Rabies" page by Colorado Parks & Wildlife.