Monitoring Endangered Peregrines in Chicago Step out on a ledge with Field Museum scientist Mary Hennen as she and her team climb some of Chicago’s tallest skyscrapers to monitor our recovering population of Peregrine Falcons. Once a federally endangered species, Peregrine Falcons had all but completely disappeared from the Midwest by the 1960s, due to the use of DDT. But over the last 20 years, Mary and her fellow team members on the Chicago Peregrine Program have helped to successfully reintroduce these beautiful birds back into the Midwest. By 2007, Illinois Peregrines totalled over 20 pairs. Spread throughout the state, the Chicagoland area has the highest concentration. Join Mary and her colleagues as they spend the summer monitoring these nest sites, tracking parents, and watching offspring hatch, mature, and fledge (take their first flight). Through these observations, scientists can determine how well their efforts are working to create a self-sustaining population of Peregrines. Before you explore the expedition website, feel free to learn more below about Peregrine Falcons, their recovery status, and what you can do to help. Take a look at our Live Web Camera that lets you peer into a Peregrine nest and check on the chicks’ progress. Peregrine Biology Decline and Recovery Status and Monitoring Injured Birds and Emergency Contact Info Frequently Asked Questions Special Thanks