Uropygial gland

A gland found in birds that secretes oil for feather maintenance

The uropygial gland, also known as the preen gland, is a specialized gland found in most birds. It is located at the base of the tail and plays a crucial role in the maintenance of feathers. The gland secretes an oily substance that birds use to coat their feathers, providing them with waterproofing and protection against parasites and bacteria.

Anatomy and Location

A close-up of the uropygial gland

The uropygial gland is typically a bilobed structure situated dorsally at the base of the tail. It is most prominent in aquatic birds, such as ducks and petrels, where waterproofing is essential. The gland consists of two main lobes that secrete oil through a series of ducts leading to the skin surface.

Function

The primary function of the uropygial gland is to produce an oily secretion that birds spread over their feathers during preening. This oil helps to maintain the integrity and flexibility of the feathers, providing waterproofing and reducing wear. Additionally, the oil may contain antimicrobial properties that help protect the bird from skin infections and parasites.

Preening Behavior

A Blue Jay displaying its uropygial gland while anting

Preening is a behavior in which birds use their beaks to spread the oil from the uropygial gland over their feathers. This behavior is essential for maintaining feather condition and is often observed in conjunction with other grooming activities, such as anting, where birds allow ants to crawl over their bodies, possibly to help control parasites.

Variations Among Species

Not all birds possess a uropygial gland. Some species, such as ostriches and emus, lack this gland entirely. In species that do have the gland, its size and activity can vary significantly. For example, aquatic birds tend to have larger and more active glands compared to terrestrial birds.

Role in Feather Coloration

The secretions of the uropygial gland can also play a role in feather coloration. In some species, the oil can enhance the brightness of plumage, which may be important for mating displays and other social interactions.

Related Pages

• Feather
• Preening
• Bird anatomy
• Anting (bird activity)

The uropygial gland of a bird

The uropygial gland of a White-winged Crossbill

A Common Hoopoe showing its uropygial gland