Thanks so much for making your files available. Based upon my own experience, I think many would agree that "documenting" is harder, and perhaps less enjoyable, than designing the actual project. The bird printout was amazingly very smooth with NO support. But, I had some trouble removing it from my TAZ 5 PEI print bed (not your fault!). A problem to be worked with 3D printers is how to get the print to stick, but, no so much (somewhat a function of the size of the base of the print) that you destroy the PEI upon removal, which I did to some extent.
I wasn't aware of the LEDs that you actually used although I regularly use the WS2801 bulbs for my outdoor displays. They can be cut apart. Polulo was out of the LEDs else I would have ordered some for possible future use. If using just a few, like you did, interconnection is not that hard. I often use a dozen or so and I would go crazy if I had to interconnect them all.
Somewhere, someone, and I'll have to find it again, used this design to also make the head movable via a servo motor. I can do servos and would like to use both the eye changing and the servo drive AND add a motion detection sensor (relatively easy). The idea would be to "swivel" the head if someone approaches or swivel every "X" seconds just for affect.
Afterthought engineering is always easier than coming up with the original design. So, thanks for doing that.