URBANA, Ill. — Bugs run rampant in the summer, and if you have ever suffered from a mosquito bite and regretted not putting on bug spray, you should know about nature’s insect repellent: the Indiana bat. Federally endangered since 1967, the Indiana bat (Myotis sodalis) helps with pest control and supports tree growth in forests, but their habitat has been shrinking.
In a recent study, researchers from Minot State University and the University of Illinois Urbana-Champaign identified factors that make trees suitable roosts, informing forest managers about strategies to help preserve the Indiana bats.
Tree size, measured by diameter, is the most important determinant for making a good shelter for Indiana bats, said lead author Joseph Pettit, associate professor at Minot State University. The age of a tree is less significant — a good thing for the bats. As long as a tree is the proper size, it does not matter how long it took to grow, meaning forest managers can accelerate the process.
“Diameter predicts which trees house the most bats,” Pettit said. “We’ve known that for a long time. Our question was specifically, ‘How can we quickly get to that diameter?’ And the answer is early-successional trees.”
Succession is the predictable process by which plant species grow and forests develop. Early in the process, faster-growing, “weedy” plants lay the necessary foundation for slower-growing species, including soil buildup, solid enrichment, and shade.
“On average, you need about 100 years if you’re going to make an Indiana bat roost tree,” Pettit said. “But there’s a little bit more nuance to it: the characteristics of the tree matter, too. Some trees — early-successional trees — can grow very quickly. They can be viable for bats in about 70 years, whereas late-successional trees typically take 130 years.”
Early-successional trees tend to be intolerant of shade, grow rapidly in the abundant light, and have short lifespans. In contrast, late-successional trees tolerate shade and typically grow in a closed-canopy forest. They mature more slowly and live longer than early-successional trees.
Both types of trees are needed in forest management practices to provide viable roosts for the Indiana bat.
“A smart management approach recognizes the importance of maintaining a combination of early-successional and late-successional trees,” said co-author Joy O’Keefe, associate professor and wildlife Extension specialist in the Department of Natural Resources and Environmental Sciences and Illinois Extension, both part of the College of Agricultural, Consumer and Environmental Sciences at Illinois. “Each provides a unique benefit that is necessary to create consistent habitats for the bats.”
Read the full article from the College of ACES.
University of Illinois Extension develops educational programs, extends knowledge, and builds partnerships to support people, communities, and their environments as part of the state's land-grant institution. Extension serves as the leading public outreach effort for University of Illinois Urbana-Champaign and the College of Agricultural, Consumer and Environmental Sciences in all 102 Illinois counties through a network of 27 multi-county units and over 500 staff statewide. Extension’s mission is responsive to eight strategic priorities — community, economy, environment, food and agriculture, health, partnerships, technology and discovery, and workforce excellence — that are served through five program areas — 4-H youth development, agriculture and agribusiness, community and economic development, health and community wellness, and natural resources, environment, and energy.