Peregrine falcon chicks change rapidly as they grow from hatch to fledge in approximately 40 days. Here are illustrations of their weekly development using photos of peregrines at the University of Pittsburgh’s Cathedral of Learning and the Gulf Tower in Downtown Pittsburgh.   At Hatching:  35-40 grams, feeble, damp, pink, sparse down, eyes closed except … Continue reading Peregrine Chicks Week-to-Week Development