Extraordinary case of chimpanzee mother caring for disabled infant

A chimpanzee mother cared for her disabled infant in the wild in Tanzania, Japanese researchers have reported. They hope the research will help in understanding the evolution of social care in humans. A team of Kyoto University researchers discovered that a “severely disabled” female chimpanzee baby was born in a group in Tanzania’s Mahale Mountains National Park in 2011, and recorded behaviour of the group for about two years. “The observed infant exhibited symptoms resembling Down syndrome, similar to those reported previously for a captive chimpanzee,” they said.

We believe the study offers a fresh clue as to how human society, which socially cares for disabled members, has evolved.

Michio Nakamura, associate professor at Kyoto University

“The mother’s compensatory care for her infant’s disabilities and allomothering of the infant by its sister might have helped it to survive for 23 months in the wild”, when the infant disappeared and was believed to have died, they said. Allomothering refers to care of infants performed by those other than the biological mother. The mother of the baby did not allow nonrelatives to take care of the disabled infant. "Other group members did not show any averse or fearful reactions to the disabled infant,“ the study said.

Usually, a chimpanzee baby can hang onto their care-giver by itself, but this infant’s legs were not powerful enough.

Michio Nakamura, associate professor at Kyoto University

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