What does "full summed" indicate regarding a raptor's feathers?

"Full summed" refers to the completion of the feather moult and hardening process in a raptor's feathers. This stage signifies that the feathers have fully developed and are ready for use in flight. The term "full summed" indicates that the feathers have gone beyond the initial stages of growth and any subsequent hardening, leading up to a point where they are at their peak efficiency.

During the moult, a raptor will shed its old feathers and grow in new ones, a process critical for maintaining the bird's flight capabilities and overall health. Once a raptor reaches the "full summed" stage, the feathers are not only new but have also become firm and robust, allowing for optimal aerodynamic performance. This state indicates that the bird has successfully transitioned through the various stages of feather development and is now fully equipped for flight.