A few years ago, four female mountain gorillas left home, abandoning not only their mate – a sick alpha money – but their babies, who were barely old enough to feed themselves. They may have felt that their children would be safer with their sick father than with new men who often kill babies from other groups. However, most mammals that abandon their mothers are at risk of early death, and researchers are concerned about the young gorillas.
Instead, the scientists found heart wonder. The youth’s uncle, a male gorilla named Kubaha, began to notice them. “He let them sleep in his nest and climbed all over the place like a jungle gym,” recalls primatologist Tara Stoinski, chief scientist at the Fossey Gorilla Intensive Fund.
Kubaha’s willingness to be a foster father is surprisingly common in mountain gorillas, according to a new study. A 53-year study of data on mountain gorillas at the Karisoke Research Center at the Gorilla Fund in Rwanda has revealed that young mountain gorillas lose their mothers – and sometimes their fathers too – who are no more at risk of dying or dying. loss of place in the social hierarchy as the rest of the group protects them from loss.
“This paper was very surprising because we know in prime ministers and most social mammals that it is very bad to lose your mother if you are abnormal,” says the behavioral ecologist. Matthew Zipple of Duke University, who was not part of this study.
A Zipple study and 10 top primatologists published last year found that young chimpanzees, baboons, and monkeys who depend on their mothers for support after their removal are more likely to die young if they lose they are their mothers at a young age. That’s because their moms feed and clean them, provide them with social support, and protect them from predators and attacks from unrelated men. Even though motherless apes survive into adulthood, they have lower social status and produce fewer offspring. Other studies have documented the same risks of maternal loss in social mammals such as killer whales, elephants, and hyenas.
But motherless mountain gorillas didn’t seem to suffer as much. Stoinski and his colleagues suggested the Gorilla Fund, including postdoc Robin Morrison, in mammals, such as gorillas, where mothers often disperse before their children mature, the social group has come forward to protect the babies from the ill effects of losing their mothers.
They tested this idea in the new study by focusing data on 59 gorillas between the ages of 2 and 8 who lost their mothers or were orphans before they were fully mature. They then compared the survival of these animals during their lifetime with the survival of 139 incorporeal gorillas. They also compared their reproductive success and social status as adults – and found out who the children spent the most time with.
Not only were the orphaned and motherless gorillas at greater risk of death, they also did not suffer long-term effects on their reproductive capacity or social status, the team reports today in eLife. In fact, some motherless men became the main male currencies of their group.
The study is “terrifying,” said lead physiologist Duke Anne Pusey, who was not involved. The data come from one of the longest mammal field surveys, she notes, and the number of orphaned gorillas is high enough for direct comparison with data from young chimps. These data show that chimps die young or suffer other side effects if they lose their mothers as women do not change groups often – and babies are more reliant on their care for longer. than gorillas.
Now, researchers need to comb up decades of data for bonobos and other species to see if they, too, accept motherless babies more often than they believed, Zipple says. A study published last week found that two bonobo women took babies from another social group in the Democratic Republic of Congo.
The findings show that altruistic behavior is not unique to humans – and that fathers play an important role in the lives of primary young people, said Duke behavioral ecologist Susan Alberts, who was not part of this study. “Inhuman prime ministers are often good fathers,” she says. “This shows that his father’s care goes deep into our private sector.”