Zoology Chimpanzee behaviors passed down through generations

Some of the complex behaviors of chimpanzees have been passed down and refined over generations. These include the combination of several tools for foraging, as a multidisciplinary study by the University of Zurich (UZH) shows.

The researchers from the universities and research institutions of Zurich, St. Andrews, Barcelona, Cambridge, Constance and Vienna traced the genetic links between different chimpanzee groups at 35 sites in Africa over thousands of years. New findings in genetics were used to uncover key elements of chimpanzee cultural history, the UZH announced on Thursday.

The researchers also collected a range of foraging behaviors. They divided these into those that require no tools, those that require simple tools, and the most complex behaviors that rely on a combination of tools. An example of a simple tool is a sponge made from a leaf to collect water from a tree crevice, UZH wrote.

Chimpanzees in the Congo use a thick stick to dig a deep tunnel through hard ground to reach an underground termite nest. They then make a tool to fish out the termites by pulling a long plant stalk through their teeth to fray out a brush-like end. They compressed the end into a point, which they skillfully inserted into the tunnel to finally pull it out and nibble on the termites that had bitten into it.

Exchange through female migration

The researchers discovered that the most complex chimpanzee technologies are most closely linked to populations that are now far away. "This is exactly in line with the prediction that such advanced technologies are rarely invented or improved and are therefore likely to be passed on between different groups," Andrea Migliano, Professor of Evolutionary Anthropology at UZH, was quoted as saying in the press release.

In chimpanzees, sexually mature females migrate to new communities to avoid inbreeding. In this way, genes spread between neighboring groups and, over centuries and millennia, to more distant regions. The authors realized that these same female migrations may have also spread cultural inventions. "These groundbreaking discoveries provide a new opportunity to show that chimpanzees have a cumulative culture, albeit at an early stage of development," Migliano said.

SDA