A new study of wild chimpanzees shows that even our closest animal relatives are mama’s boys.
Researchers found that males whose mothers were in their lives from the ages of 10 and 15 had a higher survival rate compared to those who lost their moms before they finished puberty.
Data shows that females leave their birth families behind at puberty, but young males stay longer and form more lifelong bonds with their mothers.
The young chimps may be sticking around to learn necessary skills from their mom, such as how to avoid predators or forage for food.
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Researchers found that males whose mothers were in their lives from the ages of 10 and 15 had a higher survival rate – compared to those who lost their moms before they finished puberty
‘Chimpanzees (Pan troglodytes) are long-lived mammals with a protracted period of immaturity during which offspring continue to travel with their mothers,’ reads the study published in the journal Behavioral Ecology and Sociobiology.
‘In contrast to most mammals, chimpanzees are also typically male philopatric.
‘Here, we use over 50 years of demographic data from two communities in Gombe National Park, Tanzania, to examine the survival and longevity of both male and female chimpanzees that experienced maternal loss during three different age categories.’
Primatologist Jane Goodall began observing the Tanzanian wild chimps in the 1960s.
She made notes on things like births, deaths, families and how the animals interacting with one another.
Now, a team from Franklin & Marshall Collage has gathered this data that includes information on 247 chimpanzees to understand the impact of having or losing a mother at different stages of their lives – the team collaborates with researchers at George Washington University and Duke University for the study.
Data shows that females leave their birth families behind at puberty, but young males stay longer and form more lifelong bonds with their mothers. The young chimps may be sticking around to learn necessary skills from their mom, such as how to avoid predators or forage for food
Most importantly, the data showed that chimpanzees whose mothers were still around by their tenth birthdays lived longer than their orphaned peers.
However, sons were found to have the most impact of losing their mothers at a later age than young females.
Sons whose mothers were still around between the ages of 10 and 15 were more likely to survive than sons who lost their mothers during that time, whereas daughters did just fine either way.
In Gombe National Park, half of all chimpanzee females leave their birth families behind at puberty.
But adolescent males stay put, which means mothers and sons are more likely to form lifelong bonds.
Exactly how a mom’s continued presence enhances her adolescent offspring’s survival is still unclear, the researchers say.
Unlike other animals, primates like chimps and humans take much more time to grow into adults that are capable of caring for themselves.
Primatologist Jane Goodall (pictured) began observing the Tanzanian wild chimps in the 1960s
And just like us, young chimps will stick by their mother’s sight for at least four to five years after they’re weaned.
‘Primates are unique in having a really long period of juvenility,’ said associate professor Elizabeth Lonsdorf of Franklin & Marshall College.
Young adult chimpanzees have been known to turn to their moms for comfort or reassurance after tussles with other members of their group, said senior author Anne Pusey, professor emerita of evolutionary anthropology at Duke.
She recalls a time at Gombe in the early 1970s when she saw a 20-year-old male named Figan hurt his hand during a tense encounter with another male.
‘He just went screaming to his mom,’ Pusey said.
‘The next week he traveled constantly with his mother while his hand got better.’
The researchers also believe that the young chimps could be staying with their mothers to learn survival skills, such as how to avoid predators or how to get food.
‘There’s a lot more research to be done about what mom actually does,’ Pusey said.
But the take-home is that while a mother’s role may change after the nursing years, she continues to matter even when her offspring are nearly grown, especially to her sons.
‘Even after infants are weaned, mothers still matter somehow,’ said Margaret Stanton, a visiting assistant professor at Franklin & Marshall College and first author of the study.
WHAT DOES A CHIMP’S DIET TELL US ABOUT OUR EARLY ANCESTORS?
According to the study, nutrients aquatic life provided may have inadvertently supplemented their diet with essential ingredients for brain development.
The team observed mainly females and infant chimpanzees catching and eating the crabs while the males were ‘least likely’ to eat the shellfish – favouring ants instead.
The team believe that this is because the protein and salts for females – especially when pregnant or nursing – and for growing juveniles was important.
The aquatic fauna our ancient ancestors consumed likely provided essential long-chain polyunsaturated fatty acids, required for optimal brain growth and function and eventually leading to human evolution.