Chullin 56: Birds and Becoming Treifot

A very brief note about today's daf:

Birds that would normally be considered kosher might become treifot if damaged.  But in which ways? The rabbis note that birds become treifot in ways similar to other animals as already described.  Particular to birds are their crops, which sit beside the esophagus and store/soften seeds before digestion, and gizzards.  If the gizzard is pierced, the bird might become a treifa.  But if the crop is pierced, the bird is kosher.  Even if the crop is removed completely, the bird is kosher, we are taught.