Like humans, chimpanzees use language, socialize, and mourn. Now, newly published research further establishes the link between the worlds of chimps and people: These fellow primates also have unique cultural practices, that are remarkably distinct across communities.
Researchers conducted an ethnographic analysis at 10 chimpanzee communities, discovering that the chimps' tool techniques vary when it comes to one specific, important behavior: termite fishing. Varied behavior across groups suggests cultural diversity, reports the study.
It was published Monday in the journal Nature Human Behaviour.
Termite fishing was first observed by Jane Goodall around 60 years ago. It was the first sign of chimpanzees using tools — before then, it was believed that only humans could make use of tools. The behavior involves stripping off the leaves of a twig and then using it to dig into holes in a termite mound to retrieve the tasty, protein-packed insects.
In this new study, the team collected nearly 1,500 one-minute videos of termite fishing, using camera traps. Chimps demonstrated two broad categories of termite fishing: Aerial (fishing termite nests above the ground) and underground. The scientists observed that, across 10 different communities, chimps used different techniques when aerial and underground fishing.
Take aerial termite fishing: While some chimpanzees used rigid sticks, others preferred soft ones. Some chimps gripped the twig with one hand, some used a second hand to support the wrist, while others leaned on their forearm while fishing.
Similar to how humans from different parts of the world might have different ways of saying hello or holding utensils, these different forms of fishing indicate that chimps vary across "cultures."
"The variation in community-specific combinations of elements parallels cultural diversity in human greeting norms or chopstick etiquette," the study authors write.
Relatively human – This isn't the first time chimp behavior has reminded humans of ourselves.
Other research has found that chimpanzee social interactions tend to benefit chimps personally — and that the primates will behave differently depending on who else is around.
In one particularly heart-wrenching instance, a mother chimpanzee mourned her deceased child by brushing his teeth — a ritual truly not so far off from humans grooming and embalming our loved ones once they've passed.
Taken together, it's not so surprising that chimps would exhibit yet another familiar tendency. The new study, the researchers write, "adds a new dimension to the characterization of chimpanzee cultures" and "notably decreases the gap between chimpanzee and human cultural abilities."
Abstract: Human ethnographic knowledge covers hundreds of societies, whereas chimpanzee ethnography encompasses at most 15 communities. Using termite fishing as a window into the richness of chimpanzee cultural diversity, we address a potential sampling bias with 39 additional communities across Africa. Previously, termite fishing was known from eight locations with two distinguishable techniques observed in only two communities. Here, we add nine termite-fishing communities not studied before, revealing 38 different technical elements, as well as community-specific combinations of three to seven elements. Thirty of those were not ecologically constrained, permitting the investigation of chimpanzee termite-fishing culture. The number and combination of elements shared among individuals were more similar within communities than between them, thus supporting community-majority conformity via social imitation. The variation in community-specific combinations of elements parallels cultural diversity in human greeting norms or chopstick etiquette. We suggest that termite fishing in wild chimpanzees shows some elements of cumulative cultural diversity.