The uropygial gland found in most birds protects them from water penetration, fungi, and bacteria by producing preen waxes.
Image: Alan D. Wilson /

Wood Duck (Male) , Burnaby Lake Regional Park (Piper Spit), Burnaby, British Columbia

Image: Alan D. Wilson /

Ring-Necked Duck (Female) , Santee Lakes Recreational Preserve, Near San Diego, California

“In addition to the stratum corneum barrier, glandular lipids are deposited exteriorly to the epidermis in both mammals and birds (Hadley, 1991)…In birds, ‘preen waxes’ from the uropygial are spread over feathers to prevent water penetration and ingress of bacteria and fungi. Uropygial secretions contain a complex mixture of lipids in which wax s usually predominate.” (Lillywhite 2006:219)

Last Updated August 18, 2016