Why Water birds Don’t Get Wet: Birds have a special gland called the oil gland situated near their tails. Oil from this gland is applied on the feathers with the help of their beaks. Oil and water do not mix and thus the oil prevents the birds from getting wet. This is very useful for water birds, especially the ones that dive into water to fish and get wet frequently. Some birds like cormorants and darters do not have oil glands, and have to dry their wings by spreading them out.

The behavior of birds applying oil on their feathers and grooming themselves is called preening.