Why do orca whales eat only the tongues of other whales? Evidence of their feeding is damage to the victim jaw

Answer 1

Perhaps they find that the tastiest portion.

I don't think they eat ONLY the tongues of other whales. I think they will eat just about anything softish, including fish and other parts of larger things like whales. But they may find the tongue especially delectable, and if they don't need to eat the rest, may go for another kill.

Also, the tongue is the only muscle that is attached at only one end. It may simply be easier to get to.