Never underestimate the power of motherly love. New research has revealed that male chimpanzees whose mothers died during or before their adolescence generally die much younger than other male chimpanzees.
Michio Nakamura, a professor of ethology at Kyoto University’s Wildlife Research Center, suggests that losing their mother at a young age, even after mothers wean them, deprives young male chimpanzees of both the psychological and physical support they need to survive.
“Chimpanzee mothers are known to step in to stop serious fights between males, even in boyhood or adolescence,” said Nakamura. “We have also observed juvenile or adolescent males living with their mothers for some time after they were injured. Such a dependence on female parents likely affects their lifespan.”
The study, published in the American Journal of Physical Anthropology, used “long-term demographic data for a wild chimpanzee population in the Mahale Mountains, Tanzania.” The scientists knew of 96 confirmed male chimpanzee deaths but focused on the 31 adolescent males whose mothers had died before they turned sixteen. They found an astonishing 27 died younger than the “normal” chimpanzee lifespan.
The scientists noted that breastfeeding toddlers and males younger than five years old died soon after their mothers perished and the males who were 5 to 12 when their mothers died were 2.4 times more likely to die at an early age.
Oddly, the research showed that the death of a mother affected young female chimpanzees less than males.
“…In theory at least, maternal investment in a chimpanzee son after weaning could be beneficial because in chimpanzees’ male-philopatric society, mother and son co-exist for a long time after the offspring’s weaning,” the scientists wrote in their abstract. “This suggests that long-lasting, but indirect, maternal investment in sons continues several years after weaning and is vital to the survival of the sons.”