What behavior involving tusks is thought to be a form of social bonding among males?

Answer

Tusking (gently crossing or rubbing tusks)

Observers have noted behavior termed 'tusking,' where two narwhals gently cross or rub their tusks together, which is interpreted as social bonding or a dominance display.

What behavior involving tusks is thought to be a form of social bonding among males?
animalTuskNarwhal