Thanks for your work on this mod which I am really enjoying!

In the last few days, I've been going on a bit of a tear debugging mods which are putting entries into my error.log. BCD has been adding a few relating to SELECT_TISSUE_LAYER and the Giant Leech tail attack. I think I've identified the problem and figured the fixes (with some help from the DF discord).

1. In creature_birds_desc.txt and creatures_birds_new_desc.txt,
change
[SELECT_TISSUE_LAYER:BY_CATEGORY:BEAK:BONE]
to
[SELECT_TISSUE_LAYER:BONE:BY_CATEGORY:BEAK]

2. In creature_insects_desc.txt,
change
[SELECT_TISSUE_LAYER:BY_CATEGORY:WING:CHITIN]
to
[SELECT_TISSUE_LAYER:CHITIN:BY_CATEGORY:WING]

3. In creature_birds_desc.txt change
[SELECT_TISSUE_LAYER:BY_CATEGORY:ALL:FEATHER]
to
[SELECT_TISSUE_LAYER:FEATHER:BY_CATEGORY:ALL]

In creature_riverlakepool_new_desc.txt,
remove
[APPLY_CREATURE_VARIATION:TAIL_ATTACK]
from
[SELECT_CREATURE:GIANT_LEECH]
[Alternatively, you can add tails as a body part for slam, but this seemed like an easier solution and as an added benefit makes them more bitey which certainly creeps me out.]

Also, I noticed that the default birds seem to have feet (rather than claws) so if ever go back for another pass, you might consider adding [BODYGLOSS:CLAW_FOOT] to all the birds.

I tested Crows 2.0 in the arena and they had black beaks and claws while they attacked each other so I hope this is helpful.