This feather has organic & angular elements to it, from its straight bone like center to its soft & flowing bristles. From the look of it one can assume it was plucked off of a sleeping pidgin to wake it up. The feather is not asymmetrical showing the bird to have gone through rough times.
-Peace of bottle cap:
It seems to have been stepped on & bent in a way that could look like a mouth smiling or frowning. Most likely being chewed by some squirrel before being tossed due the fact that it is not food.
With straight lines and rounded edges this object made writing a check extremely easy for someone before being lost in the abyss being their bag before being accidentally drop when they were searching for another object in their bag.