The eastern lowland gorilla is located in small pockets of tropical rainforest areas in the eastern part of the Congo. Each troop, from 7-20 gorillas, is led by a silverback male who protects and keeps the group together. Gorillas are typically quiet and gentle. Males will beat their chests as part of a ritual that sometimes includes hooting and thumping on the ground. This behavior is not clearly understood but seems to reflect excitement.
Grooming is done to reinforce dominance and submission within the gorilla troop.