What is the definition of a "brancher" in hawks?

A "brancher" refers to a young hawk that can hop between branches but is not yet fully capable of sustained, strong flight. This stage occurs after the nestling period when the young hawk has developed the basic muscle strength and coordination necessary for movement in the trees, although it may not be proficient at flying long distances.

The other options describe stages of a hawk's development but don't accurately capture the essence of what a brancher is. For example, a young hawk that can fly indicates a more advanced stage of development, while one that cannot fly at all is still in the nestling stage and not a brancher. Similarly, a fully matured hawk preparing to hunt is far beyond the brancher stage. Therefore, the correct characterization of a brancher is its ability to hop between branches as it transitions from a nestling to a fully fledged juvenile.