CFO Assists in Construction of Cave Gates
by Dave Pelren, CFO biologist
Photos by Kristen Bobo and Matt Miller

Slides displaying the progression of construction
of cave gate #2 at Haile and Dud's Caves

If you’re not into mosquitoes, you might like this project. The gray bat is one of several bat species in Tennessee that eats thousands of insects each night. As an endangered species, gray bats were in decline for several decades. One of the primary problems has been disturbance of the caves they inhabit. However, through efforts to protect the gray bat’s habitat, this species has begun to recover in numbers. The Haile and Dud’s Cave gating project hopefully will further boost its success, increasing the likelihood that the gray bat can be downlisted from "endangered" to "threatened" status and ultimately delisted. 

Cave Gate #1 - This gate was built with a high profile to allow gray bats
 to circle before exiting through the "chute" or "fly out".

Haile and Dud’s Caves are two adjacent systems located on U.S. Corps of Engineers’ property near Cordell Hull Reservoir in Middle Tennessee. These caves, known to have been visited historically by native Americans, are now important as summer habitat for the gray bat. Young bats were born in late spring to early summer in Haile Cave this year. As they mature to a flying stage, their mothers care for them in that cave. At the same time, adult male bats spend the summer in adjacent Dud’s Cave. Over time, it has been thought that human disturbances have caused the bats to abandon these caves.  The gating project was initiated to prevent human disturbance during critical periods in the bat's life cycle.

Volunteers carry angle iron to cave gate #2

The Corps of Engineers partnered with The Nature Conservancy, the Fish and Wildlife Service, the gating team of Roy Powers and Kristen Bobo, and several National Speleological Society members to restrict human access to seven cave entrances. Six gates were built (one covering two entrances) in order to accomplish this. They contain approximately 20,000 pounds of steel and took three weeks to build. The gates were designed by Mr. Powers to allow bats to enter and exit their caves in a natural manner.

Eastern Pipistrelles 

Gray bats continued to use Haile and Dud’s Caves after completion of the gates. Hopefully, an even larger number of this species and others (such as the Indiana bat, eastern pipistrelle, and big brown bat) will use the caves in years to come.

For more information about this project contact Dave Pelren at the Cookeville Field Office.