*Small memebrane coveres the opening of the [[Exotics - Anatomy of the Female Reproductive System & Physiology of Egg Formation - Anatomy & Physiology#Oviduct|oviduct]] into the cloaca in ducks, geese and swans until sexual maturity | *Small memebrane coveres the opening of the [[Exotics - Anatomy of the Female Reproductive System & Physiology of Egg Formation - Anatomy & Physiology#Oviduct|oviduct]] into the cloaca in ducks, geese and swans until sexual maturity |