Uropygial Gland

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uropygial gland

[¦yu̇r·ə¦pij·ē·əl ‚gland]
(vertebrate zoology)
A relatively large, compact, bilobed, secretory organ located at the base of the tail (uropygium) of most birds having a keeled sternum. Also known as oil gland; preen gland.

Uropygial Gland


(also preen gland, oil gland), a large, usually bilobed cutaneous gland in the majority of birds; its structure resembles that of the sebaceous glands. The uropygial gland is absent in a number of ratites, in bustards, and in some parrots and pigeons; it is highly developed in aquatic birds, especially the Procellariiformes and Pelecaniformes, and in the osprey. Located on the dorsal side at the base of the tail, it has from one to five (more often two) ducts, depending on the species. The gland’s secretion, which the bird applies to its plumage with its bill, contains lipoids mixed with proteins and inorganic salts; by maintaining the ordered structure of the plumage, the secretion prevents the feathers from getting wet. In the Procellariiformes, the musk duck, and the nestlings and incubating females of the hoopoe, the secretion of the gland has a sharp unpleasant odor, which apparently serves as protection against predators. In a number of birds, such as chickens and ducks, the uropygial gland secretion contains provitamin D—ergosterol— which the bird ingests as it preens its feathers.

References in periodicals archive ?
They then looked for the pigments that may tinge the plumage both in the secretions of the uropygial gland and on the surface of feathers.
The uropygial gland is known to produce alkyl-substituted fatty acids and alcohols that can retard the growth of bacterial and fungal organisms.
In birds, adenomas have been reported most often to arise from the pituitary gland in budgerigars (17,18) but have also been described to arise from the uropygial gland, pancreas, thyroid gland, (19) and kidney.
The chapter further describes specialized adnexal structures, such as the uropygial gland and feathers.