A study tells us that orphaned gorillas, thanks to the protection of their group, survive as long as the others, also enjoying the same social ranks.
Tara Stoinski, primatologist at the Dian Fossey Gorilla Fund, remembers. A few years ago, four female mountain gorillas left the home, leaving behind their young, barely old enough to feed.
At the time, the researcher was naturally worried. And for good reason, we know that most primates separated from their mother, and particularly chimpanzees, risk premature death. Those who survive to adulthood also integrate lower social rank and produce fewer offspring. Other studies have documented the same consequences of premature maternal loss in killer whales or elephants.
Instead, she was surprised to find that the juvenile’s uncle, a male gorilla named Kubaha, was starting to take care of them.
In reality, the transformation of Kubaha into an adoptive father is more common than you think in mountain gorillas, points out a new study. And this is not without consequences.
Within the framework of these works, Tara Stoinski and her team focused on data from 59 gorillas aged two to eight who were orphaned before they were fully mature. They then compared the survival of these animals throughout their lives with the survival of 139 non-orphan individuals. Researchers also compared their reproductive success and social standing as adults.
As a result, the young orphaned gorillas were not at greater risk of dying prematurely, or even of losing their place in the social hierarchy or their ability to reproduce. Moreover, some males having lost their mother very young became male alphas, thus dominating their own group.
“Non-human primates are often very good dads”
“The study is great“, Ruled the primatologist Duke Anne Pusey, who did not participate in this work. “The data comes from one of the longest field studies conducted on mammals, and the number of orphaned gorillas is high enough to be directly compared to data from young chimpanzees.“.
On the one hand, we know that chimpanzees die young or suffer other adverse effects if their mother is lost, while these effects are not seen in gorillas, in whom the lost protection of the mother may be. compensated by the rest of the group.
“These results suggest that such altruistic behavior is not unique to humans and that fathers play an important role in the lives of other young primates.“, Adds behavioral ecologist Duke Susan Alberts. “Non-human primates are often very good dads, ”she says. “This shows that paternal care is deeply rooted in our lineage“.
Note that a study published last week also revealed that two female bonobos adopted infants from another social group in the Democratic Republic of Congo. Also, researchers now plan to analyze the same types of data in this species.