URBANA, Ill. — Artificial roosts for bats come in many forms — bat boxes, condos, bark mimics, clay roosts, and cinder block structures, to name a few — but a new conservation practice and policy article from researchers at the University of Illinois Urbana-Champaign suggests the structures haven’t been studied rigorously enough and may harm bats in some scenarios. The article, published in Conservation Biology, lays out potential dangers and encourages more research on the popular conservation practice.

“The major emphasis among conservation managers using artificial roosts is how to attract bats, typically by modifying design or landscape placement,” said Reed Crawford, doctoral student in the Program in Ecology, Evolution, and Conservation Biology at Illinois and lead author on the article. “Their measure of success is roost occupancy or bat abundance in roosts, but we really have no idea whether artificial roosts positively or negatively affect bats compared with natural roosts. What we do know is there are multiple significant perils associated with these artificial structures that need additional research.”

The dangers associated with artificial roosts mean they could act as ecological traps in some cases, according to Crawford and co-author Joy O’Keefe, assistant 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 (ACES) at Illinois.

“An ecological trap occurs when animal populations preferentially select sub-optimal habitat when higher-quality alternatives are available,” Crawford explained. “Basically, bats could inadvertently lower their chances of survival and reduce their reproductive success by choosing poorly designed or placed bat boxes.”

Read the full release from the College of ACES.