When a badly needed freeway renovation in Pennsylvania threatened a colony of endangered Indiana bats (Myotis sodalis), the state decided to search for solutions that work for both people and bats, The Associated Press reports.
Cal Butchkoski, a Pennsylvania Game Commission biologist and longtime partner of Bat Conservation International who's studying the bats, is helping devise alternatives for the roadway. “All the data seem to indicate that it will work if done right,” he told AP reporter Marc Levy.
The problem involves a plan to build a new bridge across U.S. Route 22 in rural, west-central Pennsylvania. The AP says wildlife experts are worried that the $13 million project could lead to the Indiana bats being killed by moving vehicles at a far higher rate than they already are. If the bats are not accommodated, said biologist Bob Anderson of the U.S. Fish and Wildlife Service, the collisions “could eliminate the colony.”
The highway is a quarter-mile (400 meters) from an abandoned church where many of the bats roost at night. This colony of Indiana bats is unusual, AP reports, because it was the first colony discovered to be roosting or nursing pups in a manmade structure.
From April through mid-October each year, a few dozen Indiana bats are among 20,000 of the more common little brown bats (Myotis lucifugus) that roost in the church and a nearby bat house at the edge of Canoe Creek State Park, just east of Altoona. They emerge each night to eat insects and return before morning to roost among the rafters and eaves.
For decades now, Indiana bats have been losing habitat, such as large, dead trees for summer roosting and caves and abandoned mines for winter hibernation. Since first listed as endangered in 1967, their population has declined 60 per cent to an estimated 380,000, according to the U.S. Fish and Wildlife Service.
Butchkoski has for years been studying the little brown bats roosting at the church, which the state bought in 1993. He discovered the Indiana bats living among them in 1997. Now Butchkoski is tracking the Indiana bats' flight patterns with radio transmitters and working with transportation officials to devise a bat-friendly highway renovation.
The main problem is that the planned two-lane bridge over Canoe Creek crosses a primary flyway of the bats. If the bridge is raised, the bats, which fly close to the ground or along tree lines to avoid predators, may fly over it and into traffic. Construction could begin in 2007.
Butchkoski's idea, says AP, is to provide a large enough space beneath the bridge to accommodate the bats and to plant a fence on the top of the bridge to discourage them from flying above it. He also suggests that planting shorter trees along the highway may help funnel the bats beneath the structure.
Butchkoski said state transportation officials are also considering building a replica of the church across the highway, or even moving it there, so the bats would no longer need to cross the road.
A revised construction plan is expected soon.
