spot on Mike, i was just thinking that. Here u go Nem here is a basic blendshapes example i have...its just a basic bird in flight - nothing special but it (hopefully) kinda gives u an idea of how u can set targets

In this case the targets are wings in an upward motion and wings in a downward motion...hope it helps u out

Fiddle about with the sliders and u will see what i mean. Good luck!

btw u might wanna press play on the timline to get the bird into view first lol And if u goto display>show all you can see the targets i made...