Pied-billed Grebes have a special oil gland situated at the base of their tail. The gland is known as the uropygial gland, and secreted oil & waxes from it helps to waterproof the feathers and strengthen the bill. The uropygial gland secretes an oil (preen oil) through the dorsal surface of the skin via a grease nipple-like nub or papilla The bird will use it’s bill and head to collect the oils secreted by the gland and rub it on their feathers.
1. Pied-billed Grebe rubbing oil on it's feathers
2. Location of the Oil Gland
