I don't think they actually fire mate. If they did the lil' bird would look like an over bar-b-q'd chicken after,lol.
Being the evil minded person i am...it'd be fun to put them on a table at a garage sale and secretly film peoples faces and actions on trying to buy them for $10.
If you look at the cut-away diagram in the video it shows both barrels filled with levers and wheels that automate the bird. Also there's no flash pans to hold the powder under the flintlocks.