Social Networking 

Many humans avoid social gatherings if they don’t know anyone attending. 

So do some gorillas.  

A new study on the creatures shows that when joining a new social circle, female gorillas tend to prefer groups that include females they have previously lived with. 

“Going into a new group could feel pretty scary, with individuals usually entering at the bottom of the social hierarchy,” said study author Robin Morrison in a statement. “A familiar female might help reduce this, providing a social ally.” 

In many animal societies, members of one or both sexes leave their birth group to join a different one. In some species, including humans and gorillas, individuals may switch groups multiple times throughout their lives. 

This behavior is known as dispersal and plays a role in preventing inbreeding, promoting genetic diversity, and shaping social bonds.  

The study analyzed more than 20 years of data on multiple groups of wild mountain gorillas to discover how gorillas chose their social groups. It found that females do not disperse randomly. 

While females did not seem concerned by broad group traits such as group size or sex ratio, they considered past social experiences and avoided males they grew up with, looking for females they already knew instead. 

“Because female mountain gorillas do not know with certainty who their fathers are, they might rely on a simple rule like ‘avoid any group with males I grew up with as the likelihood of them being related will be higher than with males they did not grow up with,’” said study author Victoire Martignac in the statement.  

This rule depends not only on familiarity but on its context, she added: “This really tells us that it’s not just who they know that matters but how they know them,” explained Martignac. 

The factor that seems to matter the most was the presence of females they had previously lived with, indicating these relationships remained important even after they had spent years apart. In particular, they tend to choose females they have spent at least five years with and whom they have seen in the past two years. 

“It could also act like a recommendation from a friend,” said Morrison. “If a female they know has chosen to stay in this group, it could indicate positive things about the group as a whole or the dominant male leading that group.” 

Researchers said that maintaining relationships matters for the creatures, as temporary separations can be followed by reunions, easing the transition into new social groups. 

“This mirrors a key aspect of human societies: the existence of strong ties between different social groups,” added Martignac. “As humans, we’re constantly moving across jobs, cities, and social groups. We do it so effortlessly that we forget how unusual this flexibility actually is within the animal kingdom.”