Indiana bats (Myotis sodalis) are a state and federally endangered species. Photo by Ryan Hagerty, USFWS.
Communities Supporting Bat Communities
Enhancing maternity roost habitat for the federally endangered Indiana bat (Myotis sodalis) and other imperiled bat species is a cooperative effort.
“The Association of Illinois Electric Cooperatives (Association) stepped up to assist the Illinois Department of Natural Resources (IDNR) establish osprey hacking towers at Banner Marsh State Fish and Wildlife Area (Fulton County) and at Lake Shelbyville (Moultrie and Shelby counties),” noted Joe Kath, IDNR Endangered Species Program manager. “That experience led me to approach the Association with the idea of tackling a project to enhance the summer maternity habitat for the Indiana bat and other imperiled bat species.”
Brenda Carter, Vice President of Regulatory Compliance for the Association, approached some of the 25 rural electric cooperatives regarding interest in participating in the program.
“Cooperatives in the target areas volunteered to help establish the bat roosts as it fulfills a principle of the Association ‘concern for community,’ and they have the poles, equipment and manpower, nearly everything necessary for erecting these roosts,” Carter explained. “Norris Electric was the first cooperative to join the partnership, working with IDNR in 2021 to erect six poles at the Embarras River Bottoms State Habitat Area in Lawrence County.”
The partnership expanded in 2022 to include the SouthEastern Illinois Electric Cooperative, Adams Electric Cooperative, Wayne-White Counties Electric Cooperative, Clay Electric Co-operative and Egyptian Electric Cooperative Association. That year, three poles were erected at Saline County State Fish and Wildlife Area, four at Beadles Barrens Nature Preserve (Edwards County), three at Giant City State Park (Jackson County) and four between Siloam Springs State Park (Adams County) and Siloam Springs-Buckhorn Unit (Brown County).
About Indiana Bats
When listed as a federally endangered species in March 1967, the Indiana bat population was estimated at 914,000 individuals. In 2019, the U.S. Fish and Wildlife Service estimated that 537,297 Indiana bats occurred in 223 hibernacula in 16 states.
Annually, female Indiana bats give birth to a single pup between mid-June and early July. Pups are reared under the loose bark of dead or dying trees or live trees possessing a characteristic shaggy bark. Common tree species where maternity roosts occur include ash, elm, maple, cottonwood, oaks, and various hickory species, specifically shagbark hickory. Depending on the size of the tree, a maternity colony could contain hundreds of females. Preferred summer Indiana bat habitat includes areas with forest cover that are adjacent to a water source and open areas where the bats forage for insects.
“Indiana bats are facing a double whammy in terms of survival,” Kath explained. “First, habitat loss is impacting the quality of potential summer maternity colony habitats. Additionally, the commercialization of caves, the natural winter hibernacula for this species, and the arrival of Pseudogymnoascus destructans, a fungus causing white-nose syndrome, jeopardize the survival of bats during the winter months.”
Creating Artificial Maternity Roost Sites
Kath was introduced to BrandenBarkTM, a product produced by Copperhead Environmental Consulting, at a conference many years ago and was immediately intrigued by the concept.
“BrandenBarkTM is a thick, rubbery material that mimics the texture, color, microclimatic conditions and exfoliating nature of natural bark,” Kath explained. “The rubber sheet is wrapped around the top 3-4 feet of a utility pole, leaving a small gap for the bats to crawl under to roost.”
Addressing the potential for chemical transfer from the pole to the skin of the bats, prior to application of the BrandenBarkTM the pole is wrapped with cedar or cypress slats, which also adds a rough surface for bats to grip.
BrandenBarkTM roost poles replicate typical roost trees, with placement along the edge of the forest, where the roost receives sunlight most of the day and a roost site approximately 20-23 feet above the ground. Additional features of the roost poles include a cap on the top of each pole which minimizes moisture issues, and a metal guard about half-way up the pole which deters potential predators, such as snakes and raccoons.
IDNR staff have assembled the poles at the partnering rural cooperative’s staging area, then handed the transport and erection duties over to staff from the rural electric cooperative.
Are Bats Using the BrandenBarkTM Poles?
“Yes,” Kath proclaimed. “Bat poles are proving to be a simple, maintenance-free and cost-effective means of augmenting natural summer roost habitat.”
In the summer of 2022, examination of the six poles erected in November 2021 at the Embarras River Bottoms State Habitat Area revealed that half had been used by bats. Illinois Natural History Survey staff analyzed guano collected under the roosts using DNA extraction, revealing that, in addition to Indiana bats, samples matched the DNA of big brown and hoary bats. Elsewhere in the midwest, BrandenBarkTM roosts have been used by the federally threatened northern long-eared bat, little brown bat and evening bat, all of which are among the 13 species of bats currently recognized as occurring in Illinois.
Kath explained that the verification of a hoary bat using a roost structure was surprising.
“Hoary bats are a solitary species that roost in clumps of leaves,” he said. “This finding demonstrates the value of this research to even the common species of bats. As a whole, bats are facing a variety of environmental stressors and the more we understand their behaviors the better we can work to mitigate potential impacts.”
A Winning Partnership
This partnership is a win-win for IDNR and the Association, but perhaps most importantly it is a win for bats.
“After reporting on the project in Illinois Country Living, we received an overwhelming response from readers who became interested in the project,” said Colten Bradford, Editor of Illinois Country Living magazine, the Association’s statewide publication. “Through this partnership, people learned of the ecological importance of bats and, perhaps most importantly, wanted to become involved, often offering their own property for these roosting structures.”
Kath concurred, noting that “The overwhelming positive response in areas where the roosts were erected demonstrates that public education is a key component in our work to preserve, protect and manage endangered and threatened species.”
Kath sees the success of the cooperative bat partnership branching out in many directions.
Plans are under way to install guano catchers under some of the poles erected in 2022. Analysis of the DNA collected during the summer months will provide valuable data on where maternity colonies of the federally endangered Indiana bat occur, and also will verify the use of roosts by other, more common, bat species.
A new supply of BrandenBarkTM has been ordered and will allow the installation of an estimated 50 new poles at another five to 10 IDNR sites.
“Those new bat roosts will further expand the community of rural electric cooperatives who are participating in this partnership and members who learn about the value of quality bat habitat,” Carter added.
“We couldn’t have asked for a better outcome, especially considering the cascade of bat education opportunities that occurred,” Kath concluded. “Erecting a few poles expanded our knowledge of bat behaviors and opened conversations with landowners throughout the state who are interested in learning how to help bats.”
Kathy Andrews Wright is retired from the Illinois Department of Natural Resources where she was editor of Outdoor Illinois magazine. She is currently the editor of OutdoorIllinois Journal.