In the 1960s, peregrine falcon nesting pairs in the U.S. dropped from thousands to just a few hundred. Much of the decline was attributed to the pesticide DDT, which passed through the food chain and weakened egg shells, causing many peregrines to die before hatching. In the early 1990s, we joined the effort to re-establish the raptor by installing nest boxes at our power plants. Curtailment of chemical pesticides and success of nest boxes have helped peregrines recover. More than 230 peregrines have hatched at our nest boxes -- about 20 percent of Wisconsin’s total. You can watch our falcons during nesting season, typically March through July, on our live webcams.