In the first case of its kind, a female chimpanzee has been observed caring for an infant with severe disabilities in the wild.
The young chimpanzee was discovered in Mahale Mountains National Park in Tanzania. Known as XT11, she lived for 23 months.
She was the sixth child of her 36-year-old mother, Christina.
Physically, XT11 was similar to a captive chimpanzee that had symptoms similar to Down Syndrome.
It seems likely that XT11 only lived as long as she did because of the care provided by her mother, and that she would not have survived without it.
Reporting in the journal Primates, researchers say that the mother “responded to XT11’s abnormal behaviours, limited abilities and needs”.
She was not observed eating any plants, so she remained completely dependent on her mother’s milk long after a baby chimp would usually have been weaned.
We suspect that her feeding limitations were due to her lack of motor ability and that she might have suffered from a lack of nutrition because of her milk diet, at least in her latter life,” the authors report.
As well as her limited physical abilities, XT11 had an abdominal hernia on her stomach (see above), spinal damage and an extra, inactive finger on her left hand.