A recent survey of the Indiana Department of Natural Resources Wyandotte Cave found the hibernating endangered Indiana bat population had moved into areas of the cave not used in decades. Winter cave tours were discontinued for the first time in September 2002 to allow the rare species to hibernate undisturbed in Wyandotte Cave, one of the bats most important wintering caves.
The survey, funded by Indianas Nongame and Endangered Wildlife Program, was conducted in February under the supervision of Dr. Virgil Brack, a well-known bat expert who has studied the population of bats in the cave for over 20 years. Dr. Brack and his crew discovered hibernating Indiana bats in an area known as Bats Lodge, where they havent been seen since systematic surveys began in 1981.
"This is quite amazing," said Lori Pruitt, Indiana bat recovery coordinator for the U.S. Fish and Wildlife Service who participated in the February survey. "We have found bats back in Bats Lodge -- a historic hibernation area that hasnt been used in decades." Pruitt speculates that the absence of human disturbance associated with winter tours may have contributed to the bats movement into Bats Lodge.
Pruitt praised the Indiana DNR for its ongoing efforts to conserve the Indiana bat. "It appears that the reduction in disturbance during the winter has made Bats Lodge more suitable for hibernating Indiana bats," Pruitt said. "We hope that better hibernating conditions mean that more Indiana bats will survive the winter, and more young will be produced in the spring. We look forward to future surveys to see if bat numbers in the Bats Lodge area of Wyandotte Cave increase."
Indiana bats are extremely vulnerable to disturbance during hibernation because arousal from hibernation can cause the animals to burn more energy than they have stored for the winter. This can cause bats to die before emerging in the spring to feed on insects, or leave them unable to survive spring migration to summer habitat.
About 31,217 Indiana bats were counted during the latest survey, including 4,598 in Bats Lodge. The total is up from 28,584 found in 2001. Historically, it is estimated that Wyandotte Cave harbored more than a million Indiana bats during winter months.
The Bats Lodge area of Wyandotte Cave is named for its historic use by hibernating Indiana bats. An 1851 record mentions tens of thousands of bats "suspended from the rocks in large clusters, like bees swarming.
