Bat Work In Progress

Low poly bats coming to invade your dreams. . . 

I found my answer to the question below.  I had a shrink warp modifier I was using to try to "stick" the skin to the bones.  The animation worked better without it, and I had turned the modifier off everywhere except in the final render.  I removed the modifier and now things are working properly.

Now with video: https://youtu.be/vCcE-vW6uAE

Maybe somebody could answer me this.  It renders properly in the viewport, but the bones and skin of the wings become separated when rendering for real.

The rendered result with the skin/bone separation:

https://youtu.be/2WSX5UOYD_I