Exploring gorilla group dynamics

Hey friends, it’s Allie from the Gorilla Care Team, and today I’m going to teach you all about gorillas and their social dynamics! If you’ve ever been to Zoo Atlanta, you might have noticed that each habitat houses a different group of gorillas. Here, we have three bachelor groups and two family groups (one of them being our geriatric group). Gorillas are one of the four kinds of great apes closely related to humans: gorillas, chimpanzees, orangutans and bonobos. This being said, there are similarities and differences between the family of a human and the family of a gorilla.

When gorillas are in a group, they are often referred to as a troop. In the wild and in human care, gorillas find themselves in both family and bachelor troops. Western lowland gorilla families typically consist of around three to 11 individuals. This includes one silverback gorilla (a mature male), several adult females, and many younger juveniles, adolescents and infants. The silverback gorilla is the leader of the family, where his role is to protect, mediate conflict, and breed with the females to pass on his genetics. Under the silverback, the rest of the family forms their own hierarchy.

Bachelor troops are also found at Zoo Atlanta and in the wild. These are made up of juvenile and older male gorillas, and are formed when a male gorilla is either forced out of a family troop, or leaves a family troop voluntarily. When the male is forced out, this occurs typically because the dominant silverback gorilla doesn’t want to compete for the females, and especially doesn’t want another male’s genetics in the family gene pool. Once the males leave their family troop (whether by force or voluntarily), either the males will find a new family troop, or a bachelor troop will form between two to four individuals. This occurs naturally because not only are gorillas already social animals, but they also recognize that there is safety and survival in numbers. At Zoo Atlanta, we have bachelor troops that are recommended by the Association of Zoos and Aquariums (AZA) Species Survival Plan® (SSP). The SSP provides resources that allow accredited AZA organizations, like Zoo Atlanta, to manage and conserve threatened or endangered species. Since we have many females at Zoo Atlanta, the SSP assigns which male gorillas will live together, introducing them at early ages to increase the chances of their compatibility. If you haven’t been keeping up with our gorillas, I highly suggest you all take a look at Hayley’s recent #TakeoverTuesday on Zoo Atlanta Facebook and Instagram. The Takeover focused on male gorilla Henry and his journey to a new zoo to join his very own bachelor group!

All in all, gorillas cohabitate and communicate differently with each other in both family and bachelor troops. Though gorillas are mostly known for their famous chest-beat displays, gorillas can actually communicate in a variety of ways. This includes multiple postures, gestures, smells, facial expressions, and vocalizing over 25 different sounds! Keep in mind that certain messages can be interpreted differently, depending on the group and age of the animal. For instance, a chest-beat from a silverback gorilla in a bachelor troop might serve as one asserting his dominance in the form of a warning, while a chest-beat from a baby gorilla in a family troop might serve more as a playful popping sound. Next time you visit us, try to see the differences between each habitat and the dynamics of the individuals that live there!
Allie C.
Primate Keeper