Mike Lacki wants to put up a big "welcome home" sign for bats in Kentucky.

"Bats make important contributions to many ecological systems," said Lacki, a wildlife ecologist with the University of Kentucky College of Agriculture. "Unfortunately, they have a bad reputation due to some incorrect assumptions. Bats provide many benefits to natural systems that wouldn't be possible without their presence."

Fourteen species of bats make their homes in Kentucky. Although bats are found through the state, three sections have the highest species diversity -- the far western end of Kentucky along the Mississippi river, the Knobs region (Mammoth Cave area) in central Kentucky, and the cliff section of the Daniel Boone National Forest, according to Lacki.

Department of Forestry scientists are conducting research to identify the factors in natural habitats that are most critical for the survival of bats, especially threatened and endangered species, in order to maintain or provide adequate habitats.

"We're focusing on above-ground habitat needs," Lacki said. "For some species, an adequate habitat is an intact forest because they roost in large trees rather than caves or mines. Another area of research is on bat diets during the summer, including how diet is tied to habitat and what insects bats eat.

"Most recently, we've monitored Rafinesque's big-eared bats in Natural Bridge State Park. Since their cave is near a hiking trail, the population is subject to disturbance. We're studying the bats' responses and looking at possible ways to relieve this situation."

The U.S. Fish and Wildlife Service classifies various animal or plant species as "threatened" or "endangered," according to Lacki.

In the case of bats, an "endangered species" faces an immediate threat of total extinction because populations are so low that reproduction no longer offsets their mortality. The three endangered species in Kentucky are gray bat, Indiana bat, and Virginia big-eared bat.

"A 'threatened species' is one in which population numbers are declining," he said. "Often we don't know what factors are causing the decline and this makes it a greater concern."

Threatened species in Kentucky include the Rafinesque's big-eared bat, southeastern bat, evening bat and small-footed bat.

Lacki said one interesting facet of bats is the highly developed behavior in the roost, especially vocal communication between mothers and their young and among mothers.

"Historically, bats had been viewed as echolocators who used high-frequency sounds to create a picture of the environment to navigate and locate prey. These communications were at frequencies above human hearing. But in the roost, bats use sound within the range of human hearing for communication among members of the colony. This reflects a complex social pattern," he said.