But deterrence has its limits, and we may be facing those limits now. … In crabs, beetles, flies, and caribou—indeed, in all animals with extreme weapons—deterrence works for very good reasons, and it works only when specific conditions are met. It boils down to choosing battles wisely. It never pays to shy from a fight you might win, but it often pays to walk away from the ones you’re likely to lose. The trick lies in predicting the outcome beforehand. In order to do this, potential combatants must have a reliable method for evaluating each other’s fighting ability.

Emlen, Douglas J, Animal Weapons_ The Evoluti…, loc. 598