Flyby Attack( Masters of the Wild: A Guidebook to Barbarians, Druids, and Rangers, p. 23)
You attack while on the wing.
Ability to fly, either naturally or through shapechanging,
Adroit Flyby Attack (Dr) ,
When flying, you take a move action (including a dive) plus another partial action at any point during that move. You cannot take a second move action during a round in which you make a flyby attack. You can use this feat only while you are in a form that allows natural flight; it cannot be used in conjunction with magical flight (such as a fly spell).
Without this feat, you can take a partial action either before or after your move.