Having reared duckings for one they are born with feathers as are all fowl(chickens,geese,turkeys etc).
If you have the space and facilities to hand rear it then do.
It would not survive on it's own and is easy prey to foxes and even other birds.
Place it in a box with straw in or wood shavings(I have hand reared a duckings and goslings many a time),with a wire mesh over the top so it cannot escape.Try to rig up a source of heat,a light bulb over the box.If it is to hot it will move away from the heat ,it is trial and error to getting it just right.I always put a cuddly toy in so it has something to nestle up to.
As Lankeela said they can eat dry chick crumbs if it is slightly older.Otherwise soak the crum in water till it is like a gruel.Warning duckings are very messy eaters and poohers.Always make sure it has a fresh water supply.
If you are succesfull and it grows give it a pond in the garden,and a lockable shelter.My ducks where quite happy with a childs paddling pool(water changed daily) untill there new one had been dug out.
Good luck.