Like Humans, Chimpanzees Can Suffer for Life if They Lose Their Mother Before Adulthood
A chimpanzee mother’s presence and support throughout the prolonged childhood years allow their offspring time to learn the skills they need to survive in adulthood.
Credit: Liran Samuni, Tai Chimpanzee Project
Male chimpanzees who lose their mother early in life are less competitive and have fewer offspring than sons who continue to live with their mothers.
Researchers observed three chimpanzee communities of the Tai National Park. They kept full demographic records and collected fecal samples to conduct paternity tests on all new community members, for up to 30 years. Catherine Crockford, the lead author, says: “When we study our closest living relatives, like chimpanzees, we can learn about the ancient environmental factors that made us human. Our study shows that a mother’s presence and support throughout the prolonged childhood years was also likely a trait in the last common ancestor that humans shared with chimpanzees six to eight million years ago. This trait is likely to have been fundamental in shaping both chimpanzee and human evolution.”
Major theories in human evolution argue that parents continuing to provide food to their offspring until they have grown up has enabled our species to have the largest brains of any species on the planet relative to our body size. Brains are expensive tissue and grow slowly leading to long childhoods. Ongoing parental care through long childhoods allow children time to learn the skills they need to survive in adulthood. Such long childhoods are rare across animals, equaled only by other great apes, like chimpanzees.
Chimpanzees may have long childhoods, but mothers rarely directly provide them with food after ages four to five years when they are weaned. Mostly mothers let their offspring forage for themselves. So then what do chimpanzee mothers provide their sons that gives them a competitive edge over orphaned sons? We do not yet know the answer but scientists do have some ideas.