The Summer Bat Roost Monitoring Project uses volunteers to collect information on the distribution, occupancy and abundance of bat colonies throughout Indiana.
Participants must have bats roosting on their property or permission to enter property where a roost occurs. Possible roost sites include trees, bat houses, barns, attics, outbuildings and other structures. On each night of surveying, volunteers count the bats that exit the roost and record weather information. Each survey takes about an hour and is conducted on eight to 12 nights from mid-May to mid-July.
Long-held myths about bats are difficult to dispel, but most are unfounded. A popular misconception is that a bat will get caught in your hair.Bats are incredibly agile, however, and their use of echolocation allows them to quickly and accurately navigate through the environment. Most likely the bat is targeting an insect flying near you. Although bats can contract rabies, the infection rate is extremely low (less than 2 percent). Bats do far more good than harm. All bats in Indiana eat insects, many of which are agricultural and forest pests. It is estimated that without bats, the agricultural industry in the United States would spend an additional $3 billion annually on pest control. The long-term effects of habitat loss and pesticide use have negatively affected many bat species. Now, two emerging threats, wind farms and a disease called white-nose syndrome, are intensifying an already perilous situation. As a result, monitoring bat populations has taken on greater urgency.
Indiana’s Wildlife Diversity biologists have monitored winter populations of bats in caves and mines since the mid-1980s, but less is known about the status of bats the remainder of the year. Certain species roost colonially in structures. This provides an opportunity to study bats in their summer range while allowing the public to contribute to scientific investigations. Two species that tend to roost in structures in Indiana are the big brown bat and little brown bat. Historically, both species have been common in the state. However, white-nose syndrome has drastically reduced the population of little brown bats in the eastern United States, including Indiana.
Roost sites are critically important in the daily life of a bat. They provide shelter during the day when bats are not active. For female bats, a roost offers a safe place to give birth and rear young. If disturbed at this sensitive time, adults may abandon the roost and their young. Most bats in Indiana give birth to just one pup each year. This low birth rate makes it difficult for bats to rebound from severe population declines, like those caused by white-nose syndrome. If you have bats roosting on your property in the summer, please do not disturb them.
Information from the Summer Bat Roost Monitoring Project will help biologists evaluate roost selection, population trends, species distribution and potential impacts from disease. To learn more about this project, email helpbats@dnr.IN.gov or call the Bloomington Fish & Wildlife office at (812) 334-1137. To sign up for the project, visit the Division of Fish & Wildlife’s volunteer page and select “Find an ongoing service project.”
Wildlife Diversity staff also monitor bats using mobile acoustic surveys and acoustic monitoring stations.