By Rowan Hooper
Anup Shah/Nature Picture Library/Alamy
How many ways are there to get a termite to run up a stick? A surprising variety, it turns out. A new analysis of how chimpanzees perform this “termite fishing” has revealed that different groups of animals have distinct dining cultures, similar to how chopstick use in humans differs across the world.
The idea that non-human animals can even have culture in the sense that humans have it – behaviours and social norms that vary by group – has been controversial, but this new study firms up the idea of chimp ethnography, the study of chimp culture, as a viable subject.
Carel van Schaik of the University of Zurich, Switzerland, who was not involved in the research, says the work confirmed beyond any doubt that the variation that has been found among chimpanzees is cultural. “This paper is an absolute milestone in ‘culture in nature’ research,” he says.
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Christophe Boesch at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany and his colleagues chose to study termite fishing because it is a widespread behaviour, allowing the team to make lots of observations in different communities.
The researchers set up camera traps in 39 different wild chimp communities to record them eating termites, which they found occurring in 10 of the groups. It may be that the other communities did not have enough termite mounds in the area to display the behaviour, or simply that the cameras did not happen to capture any termite fishing.
The team carefully noted each element of the termite fishing behaviour from hundreds of video clips to create an ethogram, a behaviour profile for each chimpanzee in the study. It turns out there are 38 different technical elements all used in different combinations in each of the chimpanzee communities.
Individuals in the same community used more similar techniques compared to chimpanzees from other groups – in other words, there were local cultural differences. “As in human social conventions, you do it as you see others do,” says Boesch.
Chimpanzees in Korup National Park in Cameroon, for example, lean on their elbows to insert the stick into the termite mounds and then shake the end of the stick with their mouth to get the termites to bite the stick.
Meanwhile, chimpanzees in the Wonga Wongué National Park in Gabon lie completely on their side and insert the stick without shaking it. When extracting the stick they take the termites directly off with their mouth.
Van Schaik says the study also raises the intriguing possibility of chimp etiquette. Boesch’s team found that neighbouring chimp communities differ in the details of their fishing techniques, even though they exchange members between groups.
It seems that the differences are not functional, in that some method works better in one place than another, but cultural, and that chimps moving to a new community change their methods the better to fit in to their new social group and hasten social acceptance and integration. We don’t know, yet, if the chimps feel pressure to conform, or if there is punishment or sanctions for nonconformity, says van Schaik.
Journal reference: Nature Human Behaviour, DOI: 10.1038/s41562-020-0890-1
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