The hamadryas also differs from other baboons in its social behaviour. Instead of maintaining a large cohesive troop, hamadryas split during the day into groups consisting of a single male and his “harem” of up to six (or more) females. Unlike most species that live in one-male social units, hamadryas males use aggression both during and after takeovers to condition females to maintain proximity.

This one at the North Carolina Zoo looks pretty aggressive.

Hamadryas Baboon Staring