As an American Robin nestling develops its juvenile plumage, pin feathers emerge from protective waxy sheaths, which hold new feathers in place as they grow and dry. Once the feather is mature, the sheaths dry up, crack, and fall away or are preened away by the bird. Watch the chicks LIVE at AllAboutBirds.org/Robins. Do you have questions about American Robins and the breeding season? Join us for a live Q&A with the Cornell Lab's NestWatch project leader Robyn Bailey to learn more about robins a