A group of researchers found a chimpanzee that appears to have taken care of her congenitally challenged infant for two years with the help of the infant's elder sister in the wild. Takuya Matsumoto, lead author from the Kyoto University, believed that this is the first instance such behavior is observed.
In January 2011, a female chimpanzee that was believed to have a genetic disease was born in Mahale Mountains National Park in Tanzania. She reportedly remained immobile even months after birth. "The observed infant exhibited symptoms resembling Down syndrome, similar to those reported previously for a captive chimpanzee," stated in the abstract section of the study published in the journal "Primates."
Unable to cling on her own, the infant's mother was observed to carry her around with her left arm. "Usually, a chimpanzee baby can hang onto their care-giver by itself, but this infant's legs were not powerful enough," Michio Nakamura, Kyoto University Wildlife Research Center associate professor told AFP.
Researchers also observed that the infant's mother would not allow other chimpanzees around except for the infant's elder sibling that takes the watch when the mother eats. The infant was never seen since December 2012 and was presumed to be dead.
Conventionally, in the wild, chimpanzees born with disabilities are less likely to survive. In this case, scientists highly believed that the care the mother and sibling provided, an unlikely behavior observed among chimpanzees, has extended the infant's life.
"It is the first time it was observed in the wild that a disabled chimpanzee was receiving social care. We believe the study of fers a fresh clue as to how human society, which socially cares for disabled members, has evolved," Nakamura said.
"This will help us discover how human beings have coped with those with disabilities through the course of evolution," he added.
