Dreaming of birds usually represents phantasies, thoughts, and ideas that need freedom to come forth. Birds may represent your soul in and of itself, and various bird species may represent different symbols, e.g. owls are often associated with wisdom.
In men's dreams, the bird may represent the anima (cf Jung: anima = female aspect of the male psyche, animus = male aspect of the female psyche); in women's dreams, birds may represent the spiritual self.
And feathers are a different story. If you're adorning yourself with many colorful ones, it's time to take it easy on the arrogance and take a realistic look at your achievements. Seeing lots of feathers fly may indicate you're overspending. Gray feathers can indicate low self-confidence, and sometimes you have to let go of feathers to rid yourself of illusions.