Gliding is usually listed as an extraordinary ability, for example the Raptoran entry in RotW (pg. 68):
Gliding (Ex): A raptoran can use her wings to glide, negating damage from a fall of any height and allowing 20 feet of forward travel for every 5 feet of descent. Raptorans glide at a speed of 40 feet (average maneuverability). Even if a raptoran's maneuverability improves, she can't hover while gliding. A raptoran can't glide while carrying a medium or heavy load.
If a raptoran becomes unconscious or helpless while in midair, her wings naturally unfurl and powerful ligaments stiffen the wings. The raptoran descends in a tight corkscrew and takes only 1d6 points of falling damage, no matter what the actual distance of the fall.
Would this be considered a move-action? For example, if a Raptoran were to glide above an enemy, can it use a full-round-action to shoot it multiple times, or would gliding use up a move action, leaving him with a standard action?
What causes my confusion is the fact that there is no indication of having to spend a move-action in the original entry, and the fact that it is a special ability (I.E. not every creature with wings can glide).