April 21, 2018
Pinfeathers are starting to emerge, still furled in their keratin sheaths. The keratin sheaths help protect the growing feathers from damage and guide them as they spiral their way out through the feather follicle. D29 is roughly a quarter of the way through its time in the nest, and the emergence of pinfeathers marks the beginning of the transition from growing body parts and gaining weight to growing dark brown juvenile feathers.