I ~
I take it you found the feather lying somewhere on the ground as you don't know which bird gifted it to you? It is illegal to own certain feathers under certain situations. I can email you info on that.
Do you meditate or journey? If so, you could meditate on the feather and ask it who it's from.
Feathers (and birds) are associated with the Element of Air. Air represents the Breath of Spirit...Air supports, carries things, lifts, moves things on. The color white is associated with purity, innocence, mourning, transition, wisdom...many things. That's why which bird it is from becomes important. Each bird's Medicine is unique. A white feather from a Goose would mean something very different from one from a Swan or an Eagle.
If you would like to know how to clean and protect your feather, email me and I will send you a link.
~WhiteFox