Far from Spain, in the Amboseli National Park in Kenya, a study has been carried out that concludes that relationships with the opposite sex go beyond reproduction in the animal kingdom.

Male and female baboons during grooming in Amboseli National Park in Kenya.

Until now, primatologists have assumed that when a babuino macho is kinder to certain females is for reproductive advantages: to increase their chances of mate with them or to better protect your offspring. However, the close links between the opposite sexes can bring other benefits that have nothing to do with him sex.

A new study, published in the journal Philosophical Transactions of the Royal Society B, reveals that having female friends increases baboon survival rates. This is confirmed by more than 35 years of observation of 540 baboons in the Amboseli National Park in Kenya.

In the last decade, the scientific community had found similar patterns in other social mammals such as horses, dolphins Y orcas, but from the perspective of the females, more sociable and more deeply rooted in the same group. Males only show a partial snapshot of their lives as they come and go from these groups.

“This means that there are many gaps in our understanding of male social life “, points out Susan Alberts, lead author of the work and chair of the Department of Evolutionary Anthropology at Duke University in the USA.

Since 1971, researchers have followed the baboons in southern Kenya on a daily basis and individually, and have thus been able to detect with whom they socialized and how they fared throughout their lives, within the Amboseli baboon research project.

The Alberts team observed that males actually spend very little time preen each other, but when they do it is with the females, and not only when they are fertile. Male and female baboons who became friends spent time grooming, an activity that involves sitting together, stroking and picking their fur for parasites.

“It’s a baboon’s way of relating and relieving stress, as well as providing some help with hygiene,” says the researcher. When analyzing the data from 277 males and 265 females, The experts measured the strength of the bond between each baboon by how often they spent time grooming themselves with their closest friends.

Longer life expectancy

Using these data, they analyzed whether there was a link between friendship and the survival for male and female baboons, using statistical techniques to infer the risk of mortality. Their findings reveal for the first time that both sexes benefit from strong social ties. In the case of males, they live longer lives if they are socially connected.

According to the study, baboons who maintained great friendships with females had 28% more likely to survive another year, compared to other socially isolated specimens. In fact, the Social isolation it can be a greater threat to male survival than stress and hierarchical power struggles.

However, more research is still needed to confirm the causal fact between friendship and survival and to understand the physiological processes that allow life expectancy to be lengthened. But for scientists it is possible that the power of friendship has profound evolutionary roots in the family tree of primates.