The context I want to use it in is as follows:
Even within that confined space the chickens bustled around. Bobbing
their heads in every direction, they balanced themselves by lifting
their feet in turns from the bars. They puffed out their wings a
little as well.
Best Answer
"Puffed out" is actually a nicely creative way of saying this. Other creative choices are possible: "flung," "thrusted... sideways," "jerked," "popped," "quivered," "lifted," "spread."
Each of these requires modifying words, thus:
And so on, and so on. ("Spread" is of course the classic choice when used to describe a bird's wings opening, and you can use it effectively if you modify it carefully.)