What’s that bump by my bird’s tail? 

By Giselle Diemer

The uropygial gland, more commonly known as the preen gland or oil gland, can be seen at the base of a bird’s tail. While this gland is lacking in many parrot species (such as Amazons), it can be easily seen in African Greys and budgies and is present in most parrot species. As the name suggests, this gland secretes a clear, oily substance that is spread throughout the feathers during preening. This oily layer aids in waterproofing feathers and maintaining their condition. Interestingly, the oil may help protect against bacterial skin infections, too. 

We all know how good unfiltered sunlight is for our beloved feather kids, and this is linked to the uropygial gland. The secretions contain vitamin D precursors, and during exposure to UV light, are converted to vitamin D3, which is then ingested during preening. This ingested vitamin D is important for calcium absorption in parrots.

The gland can look different depending on species, but we have attached a couple of examples for reference. Thank you to our community for allowing us to use these photos. It is a good idea to check this gland from time to time as it can become inflamed or blocked. Always consult with your veterinarian if you have any concerns.

What does your bird’s preen gland look like?