how do you tell the difference in the sex of ring neck doves [white ringenecks]?

Answer 1

Only by behavior, or a DNA feather test. If the bird is alone it's near impossible. The male will sometimes try to get on top of another bird. He can't tell either except by behavior. A female will eventually consent to his advances, a male won't but will try to mount him sometimes.

Answer 2

The one on top is the male