Gorillas live in groups of extended families. We can consider each grouping like a small community or large family. These groups of gorillas are called a troop, or a band.
Interestingly, Gorillas share between 95 – 99% of our DNA. They are our third closest relative, after the chimpanzee and bonobos. While we might not see ourselves so closely reflected in their big hairy selves, their eyes do seem to reflect a lot of soul.
Perhaps it is this connection to gorillas that make an experience with them so incredible. Gorilla trekking adventures, where at the end of a muddy hike you get to spend a few hours face to face with wild gorilla troops, is completely unforgettable.
At first it’s scary, locking eyes with something so powerful. But it soon becomes clear that they mean you no harm, and will go about their day as you sit there marveling.
Gorillas are the largest living primate, but they are critically endangered. With only about 100 000 left of them in the wild, their survival is certainly in question, along with so many other species today.
Social Structure of a Group of Gorillas
Gorillas live in groups of extended family members. Generally there is one mature mating male per group, known as the silverback gorilla. The patriarch, if you will. However, there are multiple-male troops too.
Let’s look at the diverse ways that gorilla troops organize themselves.
The Leader of The Band
A silverback male is akin to a chief or leader. They are mature males over the age of twelve years and have silver hair along their backs, hence the name.
The silverback makes all the decisions. They also have the responsibility of mediating conflicts and protecting their troop, particularly the babies, who are in danger of infanticide from other male gorillas. They are the strongest of the gorillas.
The silverback also determines where the troop goes and where they will feed. Ultimately, the safety and wellbeing of the entire troop is their responsibility.
Lastly, of course, it is their job to mate with all of the females and produce babies. They are the only male in their troop with that privilege (possibly why other males will try to kill the babies if they get the chance).
Socialization Within The Troop
The connection between the silverback and the females of his troop forms the center of gorilla social life, as the silverback is the core of his troop. Proximity and grooming help maintain and further these social bonds.
Relationships between females are varied. Between maternally related females, interactions are often friendly. But if there is no maternal link, females often act aggressively towards one another, and there is little affection.
Male gorillas also have very varied social ties to other males. In groups with multiple males, the social hierarchy and competition for mates makes for weak social bonds. It’s often all about competition.
But we can see that this is circumstantial, because in all-male groups (which they are in sometimes when they have left their own troop and have not found wandering females) there are strong social bonds. In these groups the interactions are generally friendly, and they play with and groom one another. They even sometimes engage in homosexual interactions, which can increase the cohesion of the group.
Stable groups of gorillas rarely engage in severe aggression, as they have social bonds and the members of their troops will prevent overly damaging behavior. But when two separate groups meet in the wild, the two silverbacks can sometimes fight to the death.
Movement Between Gorilla Troops
Both females and males tend to emigrate from their original groups (the ones they are born into). Females may emigrate more than males, and both genders might even move on a second time. We can suppose that they are looking for a group that they are satisfied with.
If a troop had only one mature male and he dies, the females will disperse. A new troop can form by mature emigrating males attracting emigrating females. In this way, a completely new troop forms.
Otherwise, in a group where male gorillas have stayed in their natal troop, subordinate to the silverback, the males now have a shot. They can become the dominant male and mate with the females, and the whole troop stays together. However, this behavior has only been seen in western lowland gorillas.
In troops of eastern lowland gorillas, the females and their infants stay together until a new silverback joins the group. They are then better able to protect themselves against predators.
Parenting and Growing Up in Gorilla Troops
Females are able to get pregnant at 10-12 years of age, and males mature at 11-13 years. The gestation period is 8.5 months, much like the human 9 month pregnancy.
There are actually so many similarities between gorilla and human rearing of babies. Gorilla babies are also completely vulnerable and dependant when new to the world. In fact, they hardly break contact with their mothers for the first 5 months of their lives.
Their mothers are their main caregivers. The role of the father is socialization and protection, though recent studies have shown that they sometimes play a more active role. The silverback will shield the infants of his band from the aggression of other members.
Because of this, the mothers will generally stay close to the silverback, to keep her baby close to its protector. This makes for a close-knit family!
For the first 5 months of the infant’s life, they must suckle at least once every hour. This slowly decreases to once every 2 hours, but very slowly. Only at about 18-21 months old can the babies go so long without feeding.
In addition, the infants start to break contact from their mothers after 5 months, but only a very little bit. By 12 months old they can move up to 5 meters away from their mothers, and this steadily increases until they are only spending half their time with their mothers, at about 30 months.
Clearly then, they are slow to grow, and remain infantile for a long period. But after their third year, their juvenile period begins, lasting until their sixth year.
Last Thoughts on Gorilla Groups
Gorillas are highly intelligent and seem very family orientated, even with the competition between members. Gorillas have rich emotional lives and can develop strong bonds with one another.
Their social lives are so varied and complex, it can remind us of a rudimentary mini human civilization. If you get the chance to see these magnificent animals in their natural habitat, jump at it!