Gorillas are looking for old friends when they move

The relations established between female mountain gorillas are more important than it is understood previously, suggest new research from Rwanda.

This shows that when one of these major social monkeys enters a new group, she will seek and join another woman whom she already knows.

Scientists based 20 years of data researching several groups of gorillas in the volcano National Park in Rwanda.

Scientists found that even when two women have been separated for many years, a newly arrived gorilla would always try to join a woman with whom she had established a previous link.

The results, published in the Royal Society Journal Proceedings B, show how the relationship between two individual women is in Gorilla society.

“Scientifically, I don’t know if I can talk about” friendship “,” said the main researcher Martignac, a doctoral researcher at the University of Zurich. “But we show here that these homosexual relationships really count.”

Getting around in different groups is the key to shaping the social structure of animals. This is something that men and women do – women will sometimes move several times throughout their lives.

This dispersion, as it is called, plays a role in the avoidance of consanguinity, of the dissemination of the diversity of genes and the formation of social relations.

“In nature, it’s very important,” said Martignac.

“But it is extremely difficult to study, because once individuals leave a group, it is difficult to keep them.”

Working in partnership with the Dian Fossey Gorilla Fund, on a field site that has been monitored since 1967, Ms. Martignac and her colleagues were able to follow these movements.

Browse decades of information on the life of animals, scientists followed the “dispersions” of 56 female mountain gorillas – examining which new group they chose to join and why.

The gorillas avoided groups who had men to whom they were likely to be linked, but the presence of women they knew “also counted,” said Martignac.

Females climbed to their “friends”, even if the animals had been separated for many years.

They often climbed towards a group with women with whom they had grown up, even if it was many years ago. They also looked for people with whom they had established a social bond – perhaps played and interacted recently.

Ms. Martignac explained that gorillas would invest in these relationships because they offered key benefits.

“New arrivals generally start at the bottom of the social hierarchy,” she said. “Resident women can be quite aggressive towards them because they are potentially a competitor.”

To move around is something that is also crucial to shape human society. And the researchers say that the study of its roots in other large apes can shed light on the evolving motor forces behind.

“The movement is a large part of the way we live,” said Ms. Martignac. “But these decisions do not fossil.

“So we look at them in our closest evolving cousins.”

This new idea of Gorillas’s social life, she added, “crop back how we think of female-feminine social relationships”.

“They are much more important for these animals than we think.”