Huge colony of imperiled bats found in Crystal Valley
December 12, 2005
One of the largest populations in Colorado – and possibly all of the western United States – of an imperiled species of bat has been found in the Crystal River Valley, according to the U.S. Forest Service.The Townsend’s big-eared bat is using an old mine that tapped into a natural cave as a roosting habitat, wildlife biologist Phil Nyland of the Aspen Ranger District said Monday. He would not confirm just how many bats are living there.Studies are under way to determine how often during the year the bats use the Maree Love mine, located on the lower slopes of Mount Sopris near the Penny Hot Springs. A consultant is preparing an official report about the mine’s history for the Forest Service, but preliminary information suggests the Maree Love was a gold mine worked in the late 1880s. It apparently was abandoned for a period before it was tapped again for lead and zinc.The adits of the mine, driven horizontally into the mountainside, protrude into a hot vapor cave.Robert Congdon rediscovered the mine decades after it closed. Congdon, a former coal miner in the valley who continues to explore for minerals, holds unpatented mining claims that give him access to the Maree Love’s underground minerals. The Forest Service controls the surface rights.The agency in 2004 ordered Congdon to cease and desist all mining activities and preparatory work so it could perform a historical inventory and bat habitat study of the Maree Love; the order is still in place, according to Aspen District Ranger Bill Westbrook.Nyland said bat experts are few and far between so there is still a lot to be learned about this colony. The federal government considers the Townsend’s big-eared bat a “species of viability concern” because its habitat in mines and caves is being destroyed, Nyland said.The bats have a fight-or-flight instinct, he explained, so when they are disturbed during winter hibernation they will fly out of the cave and freeze to death.Nyland said that although spelunkers have mapped the Maree Love mine and Congdon has explored it, he isn’t accusing anyone of disturbing the bats. In fact, Congdon has assisted with the study of the bats, Westbrook said.Westbrook said it is important for an assessment to be performed before the Forest Service decides what level of use is appropriate for the Maree Love.Adult Townsend big-eared bats have a body length of only about 4 inches. However, their ears stick up 1 1/2 inches, and their wingspan is about 10 inches. They are excellent fliers that feed mostly on moths.Townsend’s Big Eared-bats are solitary creatures, except in summer when females will congregate in maternity roosts, according to material from the Colorado Division of Wildlife.Nyland said research also shows the bats will hibernate together in winter. “They will huddle up for body heat,” he said.It’s his opinion that the mine’s large rooms and geothermal heat attracted the bats; they like large spaces rather than tiny crevices, he said. And locations with heat might help with hibernation.Nyland said his recent research into the bats also shows that they have a strong instinct to return to where they were born once they start reproducing. That amplifies the importance of places like the Maree Love.Surveys of the mine and its bats are ongoing in different seasons. That data will help the Forest Service set policy on access for explorers and conditions on mining activity.Scott Condon’s e-mail address is firstname.lastname@example.org.