Scientists may have recorded chimpanzees learning skills from each other in the wild for the first time, according to a new study.
The finding supports the idea that humanity's closest living relatives can pass on culture and customs just as humans do, shedding light on the capabilities of the last common ancestor of both humans and chimps.
For decades, scientists have known that chimpanzee troops are often distinct from one another in the wild, possessing collections of behaviors that seem to form unique cultures. Researchers suggest that nearly 40 chimp behaviors are socially acquired, most of which involve various forms of tool use. [8 Human-Like Behaviors of Primates]
Prior experiments found that chimpanzees in captivity can learn new behaviors from each other, but until now, there was no direct evidence of this in wild chimps.
The research team — led by Catherine Hobaiter, a primatologist at the University of St. Andrews in Scotland — studied the Sonso chimpanzee community living in Uganda's Budongo Forest. They focused on the use of "leaf sponges," which the chimps use as tools to dip into water to drink. The Sonso chimps typically manufacture leaf sponges by folding and chewing leaves in their mouths.
The researchers noticed Sonso chimpanzees developed two variations of leaf-sponging — using moss sponges made from moss or a mixture of leaves and moss, or reusing leaf sponges that had been left behind on a previous visit to a watering hole. Neither moss-sponging nor leaf-sponge reuse had been detected in Sonso chimps in more than 20 years of observation.
Hobaiter captured video footage of Nick, a 29-year-old alpha male chimpanzee, as the animal made a moss sponge while being watched by Nambi, a dominant adult female. Over the next six days, seven more chimps made and used moss sponges.
The researchers suggest that such social learning originated in a common ancestor of humans and great apes, long before the rise of modern humans.
The findings were published online Tuesday in the journal PLOS Biology.
— Charles Q. Choi, LiveScience