To get a secondary animation on the wings you can do this with lots of different methods.

The one i would use is.

an expression.
l_wing01.rotateZ = sin (time * 10) * 40;


L_wing01 is the wing object
.rotateZ is the direction of the wing flapping

sin is returning the sine of an angle specified in radians

*10 is the amount of times per second

*40 is the degree the wing will flap inbetween.

have fun.