Brown pelican uropygial gland preening, Pelecanus occidentalis
A brown pelican preening, reaching with its beak to the uropygial gland (preen gland) near the base of its tail. Preen oil from the uropygial gland is spread by the pelican's beak and back of its head to all other feathers on the pelican, helping to keep them water resistant and dry. La Jolla, California, USA