Peregrine falcons have lived underneath the road, and in some of the bridge's rubber expansion joint, since 1989. The medium-sized hawks are protected as an endangered species in Indiana, though the peregrine falcon was removed from the federal list in 1999. State officials from the Indiana Department of Natural Resources say biologists may place nesting boxes near the Cline Avenue site to serve as an alternative home for the falcons. Adult peregrine falcons are mostly tied to the site when they nest in March and April, said John Castrale, an Indiana DNR biologist. Castrale isn't sure whether the Cline Avenue falcons are nesting in a portion of the bridge that could be torn down. He checks on the peregrine falcons every year and their nest has moved from time to time. The Indiana Department of Transportation permanently closed the bridge in late December but hasn't committed to a timetable for its demolition. Castrale plans to work with INDOT on the timing of the demolition to ensure the falcons aren't disturbed. "If they lose one nest, it's not a big deal, but we will work to minimize impact," Castrale said. "You can't really move peregrine falcons because they have a mind of their own." In the past, nesting boxes have proven successful, but Castrale said there's no guarantee the trays will be used. "If the (peregrine falcons) find that there is a lot of disturbance going on, they'll look for an alternative site," Castrale said. Spotting the peregrine falcons on Cline is usually a matter of luck for Castrale. He visits the site where they nest, which in recent years has been northwest of the Indiana Harbor and Ship Canal, about three or four times on his annual visit before he can spot them. The Cline Avenue peregrine falcons have used up to two separate nesting sites, said Elizabeth McCloskey with the U.S. Fish and Wildlife Service. She has noticed the birds in a large rubber expansion joint near the Dickey Road exit but isn't sure of the second site's location. "I knew how bad the bridge was about a year ago when we were contacted about repairing it," McCloskey said. "We told them if they were going to do repair work on it you should close off the areas where the peregrines nest." Though there's no set timetable to demolish the bridge, INDOT wouldn't be able to take the peregrine falcons' section down if the birds were actively nesting because the action would violate the Migratory Bird Treaty Act, McCloskey said. The end of the Cline Avenue bridge could also spell the end of what Carolyn Marsh of Whiting calls the highlight of her bird-watching career. For more than 20 years, Marsh has participated in a peregrine falcon watch group at the Cline Avenue bridge. Knowing the bridge will be demolished gives her a sick feeling. "We've been watching the peregrines all the way from 1990," Marsh said. "I spent hours out there watching them coming and going in crevices." (Welcome to china rubber expansion joint manufacturer)