Bats, Cities, and Trees: The Response of Midwestern Bats to the Urban Forest Gradient
Within the Midwest, many cities have greater tree density than the surrounding agricultural landscape. Trees are important for many bat species because they support the insects they forage on and provide a roost habitat. However, many city-dwelling bats roost in human-built structures, and the importance of trees for urban bats is relatively unknown. Using ultrasonic acoustic devices, we recorded bat calls from 10 species across two different projects, the 36-city Bats in Small Cities (BiSC) Project and the Champaign-Urbana Bat Survey (CUBS). We measured the response of urban bats to 1) landscape scale and 2) local scale metrics of tree canopy cover. We discovered that some bat groups had higher occupancy with higher local tree canopy cover, but occupancy was lower in heavily forested cities. In addition, we discovered that endangered Northern long-eared bats reside in Urbana, IL, suggesting that cities may provide important habitat for imperiled bat species.
