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Learning how young gorillas overcome adversity

One ongoing and fascinating area of the Fossey Fund’s research involves how adversity in early life, for example, the loss of a mother or the separation of a family, affects gorillas in the long term. We have now observed mountain gorilla families in Rwanda’s Volcanoes National Park for six generations and have seen many gorillas thrive despite emotional and physical trauma early in their lives.  

What is particularly interesting is that the resilience of gorillas we have observed is in contrast to other species where this has been studied. For example, the loss of a mother in species such as chimpanzees and orcas, even if the loss occurs in early adulthood, generally results in a shortened lifespan. But this isn’t the case in gorillas. Our 55+ year database has shown that the strong social bonds that exist in gorilla families are in part responsible for buffering gorillas from the detrimental effects of trauma. In fact, the only other species where this type of buffering has been observed is our own. 

Recently, we’ve again had the opportunity to observe the amazing way that gorillas care for those who are most in need, with two youngsters in one of the groups we monitor every day.

The story of Imbaduko and Mubyeyi

In early 2024, Kureba’s group showed us this social support system in action. Two young gorillas were left behind by their mothers, who decided to join a new group. This happened when the dominant silverback of the group – named Ishavu – began showing signs of illness. He has since recovered but during his illness, these two mothers opted to move to a group with a healthier silverback, seeking better options for their future offspring. Unfortunately, they cannot take their current offspring with them because they will not be accepted by a new male. 

Akamaro was the first to transfer out of the group, leaving behind her 2-1/2-year-old daughter, Imbaduko. Despite worries for her survival, Imbaduko showed incredible resilience, relying on the support of her brother, Karame, as well as silverback Ishavu. She is the youngest-known gorilla to survive for more than a few weeks after being separated from her mother.  Interestingly, this record was previously held by her grandmother, Umwana, in 1985.

Shortly after Akamaro left the group, another mother – Kubana – also transferred out, leaving her 3-year-old daughter, Mubyeyi, behind. Imbaduko and Mubyeyi then became close, supporting each other through their challenges. 

Mubyeyi and Imbaduko supported each other through their early challenges.

Imbaduko’s resilience also reminds us of her family’s history of overcoming challenges. Both her mother and her uncle, the renowned silverback Titus, faced early separations from their mothers, yet grew to be among the most successful gorillas we have studied. Titus also supported many gorillas in his group facing similar challenges, transforming early trauma into a pattern of empathy and support for all members of his group. 

Sadly, soon after the departure of the two mothers, Kureba’s group experienced even more changes, with female Nzeli transferring to join Mutobo’s group and Ishavu becoming separated from the four remaining youngsters. After several weeks, our trackers found two of the youngsters with an elderly silverback named Inshuti, who had been solitary for most of the last 12 years. 

Ishavu was later found reunited with another one of the remaining youngsters but the final group member was still unaccounted for as this story was posted. Our team is monitoring the situation closely and we expect there will be additional changes for some time. Please check this page for any significant updates.

Earlier cases of group support

The story of Kureba’s group brings back memories of the struggles faced by members of Isabukuru’s group in 2017. When dominant silverback Isabukuru became ill, several females transferred out of the group, leaving their young offspring behind.

Isabukuru looked after these young gorillas until he died. Afterward, Kubaha, the next dominant male, assumed the role of protector, and did a good job helping to care for and protect them.

Young Fasha faced many challenges but could always depend on her siblings to help, as shown above when they all crossed a big river. 

One memorable moment witnessed by our staff was when one of the orphans – named Fasha – had trouble crossing a river. Her sister, Icyororo, encouraged her and the rest of her family waited on the other side, making sure everyone was safe. Unfortunately, this was not her only trauma at the time; she also sustained an injury to her foot caused by a snare earlier in the year.

Another story is about Urusobe, a young gorilla from the Kwisanga family, who lost his mother last year, before he turned 3 years old. The two leading males in the group immediately began to look after Urusobe, offering comfort and care. Urusobe, showing great strength of spirit, has begun to thrive after this sad event and is now a happy and well-looked-after infant, growing up strong.

We also love the story of female Ubufatanye, who lost both her mother and father before the age of 5, as well as experiencing the disintegration of her family group. Now 20 years old, she has become a successful mother and has three offspring in her current group.

In all these examples, the support that the young gorillas received, particularly from the dominant silverback – who often was not their biological father – was key to their survival. Their support helps them not just get by in the moment but also builds strong connections in the group, ensuring a brighter future.

Once an orphan, mother Ubufatanye is now thriving with her latest offspring.

Why are gorillas resilient?

Based on decades of data analysis and ongoing research, our scientists offer some ideas about why these gorillas are so resilient, especially when compared to other mammals in which this has been studied, such as chimpanzees, elephants, whales and baboons. 

First, gorillas have very tight-knit social groups and we have seen, as in the cases described here, that when a young gorilla loses its mother, the youngster doesn’t  become more isolated but instead other gorillas help fill the gap in social companionship. The quality of these relationships is an important predictor of health and longevity. 

Gorillas also live in an environment that is rich in food resources, compared to many other wild animals, which likely decreases nutritional stress and deficiencies. 

“It is fascinating to see that the link between early life adversity and mortality in later life is not universal among species,” says Dr. Winnie Eckardt, Fossey Fund senior manager of primate research in Rwanda and one of the authors on our studies in this area.

“Perhaps gorillas will provide us with important insight into how early life conditions can shape lives, even as it relates to humans. We look forward to embarking on additional studies to help us understand the factors that may influence resilience in both gorillas and our own species.”

We are also excited to be continuing our research on early adversity in gorillas by looking at impacts on other aspects of their lives, such as reproductive success and social integration. As part of this, we are expanding our collaborations with other long-term ape research sites to see how the effects of early adversity vary by species and environment. And to further our mission to provide training for African scientists, these projects will incorporate graduate study and other research opportunities for our Rwandan scientists.