Whether it’s King Kong climbing the Empire State building or Donkey Kong throwing barrels at unsuspecting Italian plumbers, gorillas in popular culture are symbols of male power. This interpretation by filmmakers and video game creators has some truth to it. Silverback males rule gorilla troops, and occupy a place of power they only vacate after combat or death.
The first studies on gorilla behavior began in the 1950s, through the pioneering fieldwork of George Schaller and Dian Fossey. At that point, however, society had already come to believe largely inaccurate ideas about ape society. This was due to publications like Solly Zuckerman’s The Social Life of Monkeys and Apes, based partly on observations of baboons housed in unnatural and stressful London zoos. This work proposed that dominance through male sexual power was the defining feature of monkey and ape societies. Â
A new study is the latest in a long line of research to debunk such theories and show that the trope of male power is too simplistic to describe gorillas’ complex social dynamics.
How mountain gorillas break the social mold
In the wild, gorillas form small, loose social groups. Most troops are composed of a single male and a group of females. Mountain gorillas, a rare subspecies of the eastern gorilla, buck this trend. Roughly 40% of mountain gorilla troops consist of multi-male groups. Study co-authors and primatologists Nikolaos Smit and Martha Robbins set out to investigate how mountain gorillas living in the deep and ancient forests of Uganda’s Bwindi Impenetrable National Park established these complex dynamics.Â
Smit and Robbins analyzed behavioral data recorded over 25 years of close observation of four different mountain gorilla troops. They looked at recordings of intersexual interactions between the primates, specifically those where one gorilla moved to avoid another or where one took the place of another.Â
Size isn’t everything in gorilla society
Based on traditional theories of power and dominance among gorillas, males should consistently outrank females. After all, male gorillas can weigh up to 400 pounds, twice the weight of the heaviest females.Â
But Smit and Robbins noticed a more complex pattern. “Size is not absolute,” says Smit. Male silverbacks were virtually immovable, acting as the displacing animal in more than 99% of interactions.
However, females “won” more than a quarter of interactions with non-alpha males, who got out of the way of the incoming female. Females were particularly successful at winning interactions with younger or older males, despite these males still being substantially bigger and heavier than their female counterparts.Â
Analyzing the power of female gorillas
Smit and Robbins examined the factors that might predict whether a large male would move to avoid an incoming, smaller female. They found a link between a female’s time spent in close physical proximity to the alpha male. The more time a female spent with the silverback troop leader, the more likely she was to win interactions with other non-alpha males in the troop.
One interpretation of this, the authors wrote, is that alpha males and females support each other. An alpha male’s support may help increase a female’s rank within a troop, while females can use the threat of their leaving the group—and reducing the alpha’s reproductive success—as leverage to gain support from the alpha.Â
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The authors wanted to see whether this status resulted in tangible benefits for the gorillas. They looked at data on the gorillas’ feeding priority. Mountain gorillas get valuable sodium from decaying wood, and individuals take turns to eat, beginning with the alpha. Every time a female gorilla outranked a male gorilla, she ate before him. “We see that there’s a very strong influence on the feeding priority” based on this social hierarchy, said Smit.
Matriarchies in the animal kingdom
Smit is clear that the findings don’t suggest that gorillas are matriarchal, as the silverback male is still the undisputed troop leader. However, other primate species display other kinds of social structures and hierarchies.Â
Bonobos, for example, have a matriarchal structure. Female bonobos, like female gorillas, are significantly smaller than males but will band together if a male challenges them, beating the male until he recoils—costing the male social rank, and occasionally their lives. Â
A paper from earlier this year, which Smit also co-authored, looked at interactions across 121 primate species. This work showed that societies where either males or females dominate are relatively rare. Beyond primates, elephant, orca, and hyena societies all have matriarchal structures.Â
Animal researchers are still trying to find the balance of bias when studying other species from a human perspective. “I think research in evolutionary biology, behavioral ecology, and all these fields started from strong anthropomorphic views and went to something I would call anthropomorphobia,” says Smit. By this, Smit means the field is now more reluctant to assign any human-like interpretations to animal behaviors, even when there is compelling evidence to do so, such as biologist Franz de Waal’s work on animal empathy.
The challenge, says Smit, is to aim for a balanced approach while accepting that completely neutral science is a myth. “You have to be continuously careful.”
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