A new study from the University of Montana Flight Laboratory regarding the evolution of flight suggests birds evolved by learning to use their wings to run up steep surfaces in order to avoid predators and, eventually, became strong enough for true flight.

Audio Transcript:

Earning their wings . . . (SOUND EFFECT: birds flapping)

I'm Bob Karson with the Discovery Files -- new advances in science and engineering from the National Science Foundation.

(SOUND EFFECT: birds chirping) Professor Ken Dial is a bird watcher -- not the kind that tromps through the woods with binoculars and a bird book. (KILL SOUND EFFECT ABRUPTLY) (SOUND EFFECT: wind tunnel switches on) Dial looks at birds in a laboratory wind tunnel through the eye of a high-speed camera (SOUND EFFECT: quick shutter). He has studied their movements for a quarter century, and has come up with a new theory about how the earliest bird relatives first took flight.

Based on observations of modern birds, Dial thinks the elusive secret of flight may be less complex than previously believed.

Birds of a feather flocked to two differing camps on how flight evolved: one group says it came about as a result of jumping and gliding from trees. The other side believes early ancestors of birds ran and flapped their appendages until they evolved into wings.

Dial and his team are proposing a third 'flight path'. In studying slow- and stop-motion flight, they discovered that the wing angle of all birds is pretty much the same, relative to the ground, no matter whether the bird glides, climbs, descends or runs up steep surfaces. That angle is a key to the new theory about early birds: that they developed wings after many generations of using their appendages to quickly push themselves uphill (SOUND EFFECT: bird running) as they ran from predators.

Eventually one of them took off in glorious flight -- no doubt looking for the nearest car windsheild to target. (SOUND EFFECT: splat)