A mysterious egg appears in the nest of Ma and Pa Robin. The chick that hatches from it is a totally strange bird. He calls himself a "chunkwing" and refuses to eat the worms his parents try to feed him.Yet to grow feathers and learn to fly he has to eat something. He dares to jump out of the robins' nest in a birch tree and embarks on an adventurous search for the one kind of food that will enable him to grow wings. In his search...