An Ohio State class, intrigued by birds having sex, became part of an effort to save an endangered species.Doctoral student Joe Robb said he and an assistant took an introductory ornithology class on a bird-sighting walk, when he spotted an endangered peregrine falcon fly from Ohio Stadium to Morrill Tower.He said he doubts the class understood his excitement, but their interest piqued when another falcon arrived and the two began to mate.’It’s a pretty rare thing to see peregrines having sex. We were laughing and the students got a kick out of it too,’ Robb said.Robb contacted the Ohio Department of Natural Resources Division of Wildlife to inform them each time he spotted a falcon near campus.Donna Daniel, the division’s district coordinator and OSU alumna, acted upon Robb’s information.She inspected the roofs of many campus buildings for an ideal place for a nesting box.Falcons originally nested on cliffs where they could clear roosts, Daniel said. ‘Today they find tall buildings,’ she said.They often nest on window ledges and flower pots which offer little stability. Frequently, their eggs roll free or the wind takes their young.A nesting box offers safety and it enables the division to band the young and take blood samples.The division erected a box on the Arthur G. James Cancer Hospital and Research Institute Wednesday.The falcons prefer locations facing either east or south, so the box faces south, Daniel said. William Mifsud, the center’s manager of facility operations, said the division chose the center because it’s terraces resemble the shape of a cliff.Mifsud said he asked officials at the center if the birds would pose a danger to patients or research, and he was assured the falcons would not be a problem.’I just see it as another research project,’ Mifsud said.Daniel said the location was nice because it was far from other nesting sites, and it had space for the young to practice flying.’If they do have young, they have a lot of runway space,’ Daniel said.A nest box downtown on the Rhodes State Office Tower has been successful, but another nest box atop the Franklin County Courthouse failed to attract birds, Daniel said.Daniel said the lack of interest in the second box could be because it is located too close to the original and falcons are territorial. ‘There is no guarantee that the peregrine falcons will use the (OSU) nest box,’ Daniel said.The falcons became endangered after the pesticide DDT decimated their population.After World War II, farmers sprayed DDT to kill insects. Small birds ate these insects and falcons ate the small birds.The DDT weakened the reproductive systems which caused their egg shells to collapse.Bald eagle populations also suffered from DDT, but recently their numbers have increased and they have been moved to the threatened species list, Robb said.Robb said he sees bald eagles over the oval and peregrine falcons near the hospital. ‘You can see bald eagles easily in Ohio,’ he said.If the success continues, the falcons may also move to the threatened species list, Robb said.The box was installed now because the mating season is approaching, Robb said.