Nestling Development

Not all bones grow at the same pace in the young bird. Priority is usually given to the wings and legs so that the hatchling can move about the nest and exercise its flight muscles before it fledges. Usually the ribs and other bones are not fully developed when the young bird leaves the nest. The softness and flexibility of the fledglings skeleton may important for the survival of young birds that make their first flight from nests high above the ground.

Young puffins must fend for themselves when they leave the nest and head out to sea. The flight from the nest site to the ocean is little more than a short drop to the ocean. The landing is easy but the flight apparatus must be fully developed if the young puffin is to catch food. Like other auks, puffins use their wings to fly in the air and to pursue fish underwater.