Illinois

Dung Beetles Pave the Way for Wildflowers

Learn how these incredible insects help native plants at Nachusa Grasslands thrive.

Monitoring dung beetles may not be glamorous, but someone’s got to do it.

Nick Barber, Assistant Professor of Biology at Northern Illinois University, is collecting specimens at the Conservancy’s Nachusa Grasslands preserve to better understand how dung beetles re-colonize restored prairie and examine the potential effects of bison and prescribed fire on their populations.

“Until I learned of Nachusa’s bison herd, I’d never given much thought to studying dung beetles,” explained Nick. “But, my research has always focused on species interactions and there’s a very interesting interaction going on at Nachusa.”

Dung beetles play a surprisingly important role on the prairie. By burying dung, they’re putting critical nutrients into the soil where plants’ roots can access them.

“I like to say bison are the stars but dung beetles are the supporting cast,” said Nick. “As I learn more about them, I’m continually impressed that such as easily overlooked insect plays such a fundamental role. By assisting in the nutrient cycling process, these little insects help make the diverse plant communities and beautiful wildflowers of Nachusa possible.”

Fresh is Best
Capturing dung beetles is fairly low-tech. All one needs is a plastic cup, wire mesh to cover the opening and, of course, a bit of fresh dung.  These “baited pitfall traps” are then dug into the ground until the top is level with the surrounding soil.

“The dung needs to be very fresh to limit the number of other insects present. Luckily—contrary to popular belief—when it’s fresh it doesn’t smell too badly,” assured Nick.

To understand how beetle abundance and composition varies across the prairie, Nick and graduate student Sheryl Hosler set traps on remnant prairie plots and restored sites of varying ages.  Collected beetles are taken to the lab for identification and used to analyze abundance, species richness, and species composition.

Age Matters
Nick’s preliminary results found beetle abundance to be higher at older restoration sites. Apparently, like bees and snakes, dung beetles prefer their prairie slightly aged.  Abundance was also greater when bison and/or prescribed fire were present and both variables were found to influence species composition as well.

“These results demonstrate just how interconnected the prairie system really is. The plants, insects, and bison—and their responses to management—all influence each other.”

“Nick’s results are encouraging,” added Jeff Walk, director of conservation for the Conservancy in Illinois. “It’s fulfilling to see evidence that the management tools we’re using are successfully helping restore the whole prairie ecosystem, not only the plants.”

Nick’s research is also helping the Conservancy address its goal of supporting diverse ecosystems by studying an underappreciated, but functionally important, organism in a rare habitat.

“The staff and volunteers at Nachusa are amazing. I’m always bragging to other ecologists about how special of a place Nachusa is and how supportive the Conservancy has been of science.”
 

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