Noun
English Wikipedia has an article on:uropygial glandWikipedia
uropygial gland (plural uropygial glands)
A secretory organ, at the base of a bird's tail, that secretes the oil used in preening.
In some birds, feather colors may be created, or altered, by secretions from the uropygial gland, also called the preen gland. Source: Internet
Like most other ratites, they have no uropygial gland (preen gland). Source: Internet
The only cutaneous gland is the single uropygial gland near the base of the tail. Source: Internet