Glacier National Park supports nine species of bats, of which the most common is the little brown bat. Although they are often the objects of fear, bats in Montana have a very low incidence of rabies, and they are an important part of the food chain. As insectivores, they regularly consume one third of their body weight in insects during a nocturnal feeding period. Many bat species have sophisticated echolocation mechanisms to find their prey in the dark via sound waves. With the approach of winter, some species fly to warmer areas, while others remain to find safe roosting sites and go into torpor, slowing their body functions down until roused by warm weather.
A researcher holds a little brown bat
When bats are captured, researchers note their age, sex, weight, size, and other factors to determine their overall health.

NPS Photo

Research and Monitoring

Until recently, very little was known about bats in the Crown of the Continent, including what species are present here and what their population sizes are. However, the threat of white-nose syndrome (WNS) has spurred significant efforts to learn more about our bats. This disease is one of the most destructive wildlife epidemics in history, having killed an estimated six million bats.

WNS is caused by a fungus (Pseudogymnoascus destructans), and it is identifiable by a white residue on the nose and wings of affected animals. It attacks hibernating bats by upsetting the way they regulate their temperature, causing them to come out of hibernation during the winter months. Without food and water sources available, most of these bats die.

As of 2018, WNS has not reached Montana, but it is present in neighboring states. In the face of this threat, Glacier’s scientists have worked to establish baseline data about the park’s bats, using acoustic surveys for remote detection and species identification, and mist-netting for live captures to assess individuals’ health. In addition, surveys have confirmed that bats use at least one cave in the park, and continued monitoring will assess other potential roosting and hibernation sites.

Additional Resources

Last updated: September 13, 2018