How do seagulls stay so white?

Answer 1

They produce an oil from a gland under their tail that protects the feathers. It keeps dirt and other oils from sticking to them. They actually can get stained, but it doesnt happen often.

By the way, not all gulls are white. Young gulls can be quite dark. Some species, such as Heerman's Gull, are gray.

Answer 2

they have a bath every 20 minutes .and then get bleached in the sun