Gorilla Families Come Together to Care for Young Orphans, Study Suggests

Mountain gorillas help care for young group members if they are orphaned without a mother, a new study suggests.

The researchers behind the study say the behaviour is similar to how humans help care for the children of other family members, or even the children of non-relatives.

This shared behaviour may even point to similarities in the DNA of both humans and gorillas.

In all mammal species, the role of the mother is important for the survival of offspring in the early stages of life, the study states. As such, individuals that are left without a mother tend to suffer higher mortality or be less successful parents, according to Robin Morrison, the study's lead author and researcher at the Dian Fossey Gorilla Fund.

"But our research shows that mountain gorillas really go against this trend," she said.

The study involved Morrison and the team looking at 53 years' worth of data gathered by the Dian Fossey Gorilla Fund to examine the effects of maternal loss.

The study found that mountain gorillas, which live in tightly-knit family groups, had no greater risk of dying if they lost their mother between the ages of two and eight and also did not appear to become worse parents themselves.

The study also found that when mountain gorillas lose a mother, the number of interactions they have with other members within their group increases significantly.

The researchers think these two findings are linked; the increase in group interactions could help reduce the negative effects of losing a mother.

The study states: "In contrast to most social mammals, where maternal loss causes considerable social adversity, in mountain gorillas, as in certain human populations, this may be buffered by relationships within cohesive social groups, breaking the link between maternal loss, increased social adversity, and decreased fitness.

"It seems that gorilla social groups, like human families, provide support to young group members that lose their mothers."

Orphaned gorillas formed particularly strong relationships with the dominant male of the group and with young gorillas around the same age as themselves. The study found silverback males played an important role in supporting young motherless gorillas even if they were not their genetic fathers, by engaging time spent resting and grooming.

This shared social caring behaviour may point to evolutionary links with humans, according to Morrison. She said in a statement: "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."

The study notes that further understanding of this behaviour "could provide clues into the social mechanisms that help to overcome early life adversity, and have a positive impact on future health and survival."

The study, titled "Social groups buffer maternal loss in mountain gorillas" was published March 23 in the journal eLife.

Gorillas in forest
A stock photo shows two gorillas together in the Bwindi Impenetrable Forest in southwestern Uganda. NickJackson2013/iStock