Saw a magpie do an ABSOLUTELY PERFECT stall turn at about 30 feet a few days ago. Of course he was pulling some evasive manouevers to break away from the 3 bandits on his tail... you'll be happy to know he was successful, and lived to continue his air-combat for another day.
OK, now if a bird claps its wings over its back (just asume it can) then it would fall body first with wings trailing - i.e. pendulum effect could have something to do with it. I figure it would just pile on a heap of dihedral, and alter it to suit. Remember it can
feel how much lift each wing is producing. If it has some dihedral on then when one wing has more lift it's obviously banking so it corrects. It also knows when it's going to stall too, its feathers will get all ruffled or something, and it squaks to simulate the stall warning horn...
and will compensate with its tail to alter pitch.
This is all a hypothesis, but I'd tend to go more with this possibility that it sensing magnetic fields and seeing UV light. Not saying anyone's wrong, just my thoughts.
Turbofan
P.S. I've also seen a hawk do a few great snap-rolls when I
snuck up on it in a Blanik (glider).
Good question Stallie.