trying to find tutorial on slowing down close up bird footage

I am trying to use Twixtor to slow down some close up bird footage. I have come across a few tutorials, which gives me the general idea how to use the program, but nothing really specific on birds. The problem I'm having is mainly as the wings flap and cross the bird body, it causes the body to warp to match the wings. I've tried to roto the bird and wings frame by frame in keyframes, but I still get a lot of warping. I have Twixtor and Twitor Pro as plug-ins for AE CS4.

Thanks in advance for any help,
Jon