In an effort to protect the largest known bat refuge in Maryland, state officials planning a 4.7-mile extension of the Western Maryland Rail Trail have decided to detour cyclists around an abandoned railroad tunnel where hundreds of bats winter.
Tourism interests in the region had hoped the 4,350-foot-long Indigo Tunnel would become a prime attraction for bicyclists pedaling west from the trail's current terminus at Pearre. But biologists discovered its rock walls are home to an estimated 1,400 hibernating bats, including some rare or endangered species.
State officials said Monday that the 106-year-old tunnel will be fitted with bat gates next spring to keep people out, while allowing the bats to come and go freely. The measure is designed to keep the bats from being disturbed by cyclists and to prevent introduction of disease. Work on the trail extension will begin in 2012.
"That's a win-win solution," said James Kennedy, a biologist with the Texas-based Bat Conservation International. "The bats obviously are going to be much happier without any disturbance. And if the cyclists are still accommodated, that's wonderful. It's a nice scenic stretch of the towpath."
The bats face peril from a fungal disease, called white-nose syndrome, which has destroyed bat colonies elsewhere. The disease was found in Maryland earlier this year, but has not been detected at Indigo Tunnel.
Bike traffic approaching the tunnel will be detoured onto a ramp to the unpaved C&O Canal towpath. After about a mile and a half, cyclists will be returned to the old railroad bed just west of the tunnel, said Harvey Bryant, project manager for the Department of Natural Resources.
The decision won't be official until the National Park Service completes an environmental assessment of the $4.6 million trail project in about nine months. But Bryant said the DNR and the park service have agreed: "We absolutely know which way we're headed. We're going around."
Emma Royds, a Hagerstown resident who has been riding the trail for 10 years, said based on her conversations on the trail, she believes cyclists would "much rather enjoy a few more miles of scenic, outdoor trail than to pedal through a mile of dark, damp tunnel. When you add in the fact that there are special bats in the tunnel, it was really shocking that a project like this was ever even proposed."
Indigo Tunnel was abandoned by the Western Maryland Railway in 1975. Its 20-foot rock walls and wood cribbing have attracted numerous species. One is the eastern small-footed myotis. Listed as endangered in Maryland, it has been devastated by white-nose syndrome in its two largest hibernacula, both in New York State. Indigo Tunnel is thought to be its largest remaining refuge.
Other species known to winter in Indigo Tunnel include little brown bats, big brown bats and eastern pipistrelles. Trap surveys suggest others as well, including the federally endangered long-eared and Indiana bats.
Bats play important roles in plant pollination, seed dissemination and pest control. One little brown bat can devour 1,000 mosquito-size bugs an hour. They also eat agricultural pests.
Biologists have been monitoring Maryland's bats closely since the outbreak of white-nose syndrome. Since its discovery in 2006, the disease has killed more than a million bats nationwide.
Scientists say it's likely that bat-to-bat contact is helping to spread the disease. But its rapid advance has raised alarm that cave explorers may also be transporting it on their clothing or equipment.
Richard Cushwa, a director and former president of the Cumberland Valley Cycling Club, said a detour onto the tow path would pose difficulties for cyclists on thin-tired road bikes.
"A possible solution is to install a tight-packed crushed stone surface … for the length of this detour," he said. It would "accommodate road bikes very well, and should not impact the historical nature of the Canal."
But Bryant minimized the issue. "We'll probably have to put signs up to let them know it's a little more rugged," Bryant said. But "the majority of people who ride are not riding Tour de France bikes. Most are a hybrid or mountain bikes anyway."
Eventually, Maryland and West Virginia hope to extend the trail another 10 miles to Paw Paw, following the old rail beds, crossing the Potomac six times and passing through the old Stickpile and Kessler tunnels, neither of which hosts bats.