Indiana bat research in Pa. draws national attention

HARRISBURG, Pa. – Pennsylvania Game Commission researchers have uncovered new information about a longstanding endangered species of bat that has become a direct beneficiary of intensive conservation efforts at Canoe Creek State Park in Blair County.

Indiana bats have maintained a fragile existence in Pennsylvania for decades. They were one of the state and nation’s first designated endangered species, and have been perennial ringers to remain on the federal endangered species list for more than 30 years.

So in 1997, when Cal Butchkoski, game commission wildlife technician, first noticed Indianas taking advantage of specially designed and managed bat structures at Canoe Creek State Park, it drew considerable attention among the Commonwealth’s bat managers.

The discovery begged the question: Were Indianas using buildings as sites for maternity colonies?

Roosted only in trees.

“Up until that point in time, Indiana bats had never been documented using a man-made structure as a maternity roost,” said Jerry Hassinger, wildlife diversity supervisor for the agency’s bureau of wildlife management. “They had historically been observed using only trees for roosting. It was quite a find.”

But it also sparked plenty of questions. To answer them, the state needed to substantiate and measure the use. “We wanted to know if Butchkoski’s observation was a chance occurrence, or if Indiana bats were showing us something new.”

Over the past decade, state biologists have made tremendous headway in developing management plans for Pennsylvania bats. A significant portion of that work involved bats at Canoe Creek State Park, which is managed by the state Department of Conservation and Natural Resources’ Bureau of State Parks.

Bat condo.

Canoe Creek is where the game commission, in 1995, built its famous “Bat Condo.” The condo can accommodate up to 5,000 bats, and is near the equally renowned Canoe Creek Church.

Bought in 1993 by the Wild Resource Conservation Fund, the 19th century building houses the state’s largest maternity colony of little brown bats in excess of 20,000 – over summer.

Also found on the park is the abandoned Hartman Limestone Mine, which harbors more than 20,000 hibernating bats over winter and is the state’s largest known bat hibernaculum, or hibernation site.

Historic visit.

Work to establish whether Canoe Creek Church had the first-ever known Indiana bat maternity colony in a building began in June 1999 with funds provided by the U.S. Fish and Wildlife Service. The study kicked off when field researchers went into the church’s attic and searched for endangered Indianas hidden among thousands of little brown bats.

The entry and subsequent visits were historic; and it would later be recognized as the first time ever that researchers knowingly went inside an Indiana bat maternity roost.

“It was a tough job finding Indianas among the little browns,” Butchkoski explained. “The attic is very hot and has poor ventilation, but it is an ideal place to conduct research. Sharing the attic with thousands of bats wasn’t a problem. They’re really very passive creatures.

“There is a way to identify Indianas among the throng of little brown bats clustered in the attic, but the ability comes from years of experience. There’s a slight pelage difference for Indianas; they’re somewhat grayer than little browns.”

Bat bands.

From June 1999 to July 2000, 29 Indiana bats were found using the church attic. Each was banded on the forearm to document long-term roost and hibernaculum preferences. In addition, transmitters were glued onto seven Indianas captured at the church. Their movements were monitored daily and nightly to provide insight into bat behavior and habitat use.

Six females and one male received transmitters, which weigh about half a gram and fall off within two weeks. One of the females gave birth to a pup in the church, proving conclusively that Indianas were using the church attic as a maternity roost.

Monitoring the transmitter-tagged bats turned up a variety of unique Indiana bat findings. They include documentation of: the first Indiana bat maternity colony found in a building; the first known shared maternity site used by little brown and Indiana bats; an Indiana bat entering the Bat Condo; and summer habitat use of Indiana bats in Pennsylvania.

The bat’s primary range is in the Midwest. Loss of and disturbances to wintering sites – typically caves and mines – have plagued Indianas.

They’re also impacted by the perpetual loss of summer maternity roosts, which are typically found under the loose bark of and in the cavities of trees. It’s been estimated that as much as one third of these sites are lost annually when these roost trees are blown or cut down.

Telemetry showed that the Indiana bats using the Canoe Creek Church roost also used trees as alternate or secondary day roosts. However, their young – frequently referred to as pups – were born and reared in the church.

Research also documented that Indianas avoided nearby mountainsides, steep slopes and small woodlots. They foraged mainly in a large block of mature forest with short or gradual slopes and small streams.

To learn more about Indiana bats, visit the “Endangered and Threatened Species” section of the game commission’s Web site at www.pgc.state.pa.us.

Click on “Wildlife,” then “Endangered and Threatened Species.” Information about all Pennsylvania bats can be found in the “Wildlife” section by clicking on “Assorted Wildlife Notes,” and then choosing “Bats.”