When I first heard of the town of Cave Springs as a child, I immediately wondered whether there was a cave there, and, if so, what types of creatures inhabited its cool, dark depths. People are naturally drawn to the primeval and the wild unknown, and Cave Springs Cave at the Illinois River Watershed Sanctuary is no exception.  People of all ages gravitate toward the cave when they visit this site– its frigid spring water cascading over mossy rocks, the chilly gusts of misty air, and the ferns and wildflowers blanketing the limestone bluff.

Gray bats at Cave Springs Cave exiting for their evening feast and flight.

Something that truly fascinates me about Cave Springs Cave is that it is home to two threatened and endangered species.  The gray bat is one of these endangered species, which means that it is in danger of going extinct.  Habitat loss and human disturbance are perhaps the greatest threats to gray bats, and for that reason, Cave Springs Cave has been closed to the public for nearly three decades.  A bat-safe gate surrounds the mouth of the cave, allowing people to view the bats from a safe distance while causing no disruption to their evening flight. WP_20131004_010

 This gating allows a close-up view of the cave without posing a threat to the endangered bat population.

In the summertime, gray bats roost in caves with an abundance of water nearby, as they predate on the insect populations that tend to thrive along lakes and rivers.  This makes Cave Springs Cave an ideal summer habitat!  The cool, consistent spring water forms the lake at the Watershed Sanctuary, which then spills into Osage Creek.  The typical nightly flight radius of this species is around 30 miles, and, according to the Arkansas Natural Resources Commission, the bats at Cave Springs Cave follow Osage Creek all the way to the Illinois River to feed each night!

Gray Bat, Adam Mann, Environmental Solutions and InnovationsGray Bat, Myotis grisescens

Saturday, August 23, 2014, was International Bat Viewing Day, and it marked the 2nd annual Bats and Bluegrass celebration at the Illinois River Watershed Sanctuary.  Nearly 300 people set up blankets and lawn chairs along the shady northern lakeshore to enjoy a live performance by Fayetteville bluegrass quartet, Arkansauce, before taking a night hike to Cave Springs Cave for a spectacular bat viewing with night vision equipment from the U.S. Fish and Wildlife Service. BatsBluegrass2

Hundreds of visitors gathered at the Watershed Sanctuary for Bats and Bluegrass on Saturday, August 23, 2014.

In mid to late September, the bats will leave Cave Springs Cave to begin their seasonal migration to Cave Mountain Cave, their winter hibernacula located near Boxley, Arkansas.  This cave is more suitable for hibernation because it is larger, cooler, and has better airflow.  This allows the bats’ body temperatures to stay cool enough for their fat reserves to last for the entire hibernation period.

The endangered gray bats are just one of the many unique wonders of the Illinois River Watershed.  As we bid our seasonal adieu to the bats at Cave Springs Cave, we look forward to the spectacles to come with the next season at the Watershed Sanctuary.

Illinois-River-WSCS


Additional Resources:

Gray Bat Facts, U.S. Fish and Wildlife Service

Cave Springs Cave Natural Area, Arkansas Natural Heritage Commission

Watershed Sanctuary and Learning Center, Illinois River Watershed Partnership