This design originated at the beginning of the 20th Century and originally they would have been lined with silver mercury solution. Made in the same way using traditional glass blowing techniques and antique molds, these are now individually hand painted, finished with glitter and realistic feather tails. These have little spring clips to attach to tree branches. Each piece is an individual work of art. 
With the tail, these measure around 6 inches in length.

Czech blown glass bird Christmas feather tree ornament red gold. This listing is for one bird only, not a set of 6