Field Museum scientist Mary Hennen had the chance to band a rare peregrine falcon hatchling earlier this month. The bird was living in a nest on top of the 53rd floor of a Chicago senior living community when Hennen retrieved it for tagging and a blood test. She determined that the falcon was 32-35 days old, just a week away from its first flight. Hennen then immediately returned the bird, whom building residents named Clare, to her parents' nest. The Museum staff will continue to monitor the falcons, three of 27 living in Illinois. To see ABC-7’s coverage of the story, click here.