silverback
An adult male gorilla with silvery-gray hair on its back.
A silverback is an adult male gorilla whose back hair has turned silvery-gray with age. This silvering happens when a male gorilla reaches maturity, usually around 12 years old, marking him as a fully grown adult. The silver fur runs across his back and hips, like a gray saddle.
In gorilla society, the silverback leads his family group, which scientists call a troop. He decides where the group travels to find food, where they'll sleep each night, and protects them from danger. A silverback might lead a troop of 5 to 30 gorillas, including females and young gorillas. When two silverback males meet, they sometimes compete by beating their chests and making loud displays to show their strength.