Young gorillas without mothers get extra support from their group

Gorilla families come together to support young gorillas that lose their mothers, according to a new study from the Dian Fossey Gorilla Fund. The researchers used more than five decades of data to investigate how maternal loss influences relationships, survival, and future reproduction among young mountain gorillas. 

“Mothers are incredibly important for survival early in life – this is something that is shared across all mammals,” said study lead author Dr. Robin Morrison. “But in social mammals, like ourselves, mothers often continue to provide vital support up to adulthood and even beyond.”

“In many species, like our close relatives, chimpanzees, individuals without mothers suffer higher mortality or may be less successful parents themselves, and this finding can hold even if the loss occurs in early adulthood. But our research shows that mountain gorillas really go against this trend.”

Between the ages of two and eight, young mountain gorillas are able to feed themselves but are not fully mature. The study shows that gorillas orphaned at this point in life do not have any greater risk of dying than those who still have their mothers.

The researchers found that maternal loss does not seem to have any long-term effect on the gorillas’ ability to reproduce and rear offspring. In addition, the experts discovered that interactions between young gorillas and other group members increases dramatically after the loss of a mother. 

The study authors suggest that this support from other gorillas may be similar to what we see in humans, where family members and non-relatives step into key roles to care for children. For example, male gorillas are known to care for young members of their group, regardless of paternity. 

Dian Fossey once noted that “the extraordinary gentleness of the adult male with his young dispels all the King Kong mythology.” The new research confirms this statement, finding that the dominant silverback male plays a particularly important role in supporting young motherless gorillas. These males were observed spending more time close to the orphans, engaging in activities such as resting and grooming together. 

“These findings suggest that our capacity to care for other group and family members in times of need may be deeply rooted within our DNA and something we share with gorillas,” said Dr. Morrison.

The researchers analyzed data on mountain gorillas dating back to 1967, when Dian Fossey first established long-term monitoring.

“This study highlights the value of long-term research on wild animal populations” said Dr. Tara Stoinski, CEO and chief scientist of the Dian Fossey Gorilla Fund.

“Just like us, gorillas live long lives, so it takes years for researchers to record the rare and fascinating behaviors that occur over a gorilla’s lifetime. Our dataset, one of the longest of any animal species, stretches back more than 50 years, helping us understand how much we share with one of our closest relatives as we work to protect them and their biodiverse habitat.”

The study is published in the journal eLife.

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By Chrissy Sexton, Earth.com Staff Writer