What are some physical and behavioral changes that occur in Drum, Lady, and Duchess with evidences from the text in Frightful's Mountain?

By the time they're five weeks old, Lady and Duchess have grown to be as large as Frightful and Chup. They are picky about what they eat, although they come to enjoy small game as much as birds. They also begin to half-jump and half-fly small distances. Eventually, they begin to fly greater and greater distances, while Frightful watches over them carefully.