Here is the head paper mached (damn, been 3 years since I did paper mache...I do not miss the gooey mess, lol) many a layer with tacky glue and newspaper, and a layer of wood glue and paper bag. I JUST cut along the jaw line and under the eyes/above the cheeks and popped the 2 parts off...it worked! never tried it before, never heard of it done, and it worked, and I can make more if needed by using the same foam head!
I am still not sure if I can get the jaw to move though :< I need to expeirment with cutting through vs above the cheeks because right now, wow does it look odd to hold the 2 pieces with the mouth open, it opens under the eyes D: I need to let this dry a bit longer before I mess with the jaw, the bottom/inner most layers are still damp and I do not want to distort it.
this may be the last WIP you buzzards get for a while, I feel like I am spamming everyone with this damn bird.
if you don't seal them (moisture kills them otherwise) or do enough layers (thin is brittle) or treat them nice. I have paper mache heads and fake taxidermy creatures that date back to 2001, but they have been well taken care of (and paper mache is not something I use on customer orders because it needs too much tender loving care to stay nice)
I think I spammed my watchers with my minotaur more than you have with your bird lol. I love seeing this come together, and I can't wait to see it finished!