You can find that info here: [LORE]Item Enhancements[/LORE]
Oh, there bonus damages... though... if arrows/bows already do piercing... wouldn't the Falcon feathers piercing bonus be a bit well... useless... or am I reading that wrong and the damage type from feathers actually change the base damage type?
Also... bit off topic but... how exactly does feathers change damage type? Sorry I tend to think well... realistically at times. Slashing, Piercing and bludgeoning (at least)seems to me more to do with how the arrow head is crafted.
Piercing: smooth yet sharp edge with the tip being the smallest sharpest point.
Slashing: Flat and wide for the most part with serrated edges to rip into the target.
Bludgeoning: Little more then a small round metal ball for an arrow head.
At least those are my thoughts.