I attempted to make Terror Birds and Dodo Birds shed feathers using your mod, but, upon viewing their entries in the guide, I get this crash:

http://pastebin.com/hbEB6AqJ

I put the content in right and anything, its just that they crash upon being viewed in your guide.

I had them set up something like this:

# Configuration of Shedding for fossil.TerrorBird
S:fossil.TerrorBird.item=minecraft:feather
I:fossil.TerrorBird.lexiconDisplaySize=40
I:fossil.TerrorBird.metadata=0
I:fossil.TerrorBird.rate=24000

What mod is the terror bird from?
EDIT: Apparently I fail at reading. I'll check it out.