A young male gorilla is called a blackback, and an adult male gorilla is called a silverback. The oldest and strongest silverback is typically the dominant male in a group.
The dominant silverback leads a group of gorillas called a troop. This male is responsible for the well-being of all the troop members, which includes females, males and offspring. The silverback decides where the troop eats, when they rest and where they sleep.
When a younger male from another gorilla troop challenges the silverback, he beats his chest, bares his teeth and screams. He will also shake branches and charge forward to scare the intruder away.