Providing Water for Birds
Like all animals, birds need water to survive. Though they can extract some
moisture from their food, most birds drink water every day. Birds also use
water for bathing, to clean their feathers and remove parasites. After splashing
around in a bath for a few minutes, a bird usually perches in a sunny
spot and fl uffs its feathers out
to dry. Then it carefully
preens each feather,
adding a protective
coating of oilsecreted by a gland
at the base of its tail.

Copied from Cornell Edu.