The world gasped for air for the first time the news broke: Chimpanzees use tools, just like humans! This was, when, back in the 1960s, Dr Jane famously reported on chimpanzee David Greybeard. David broke a twig from a tree, stripped it from its leaves, and inserted it into a termite mound. The termite soldiers did a good job in defending their mounds by instantly attacking and biting the intruding object. It was an easy task for David to then pull out the stick, which was covered in fierce termites clinging to it, and eat them with gusto.
Although today we know that many animals make and use tools, including some mammals, birds, molluscs and reptiles, tool use had been viewed at the time as quite simply defining humans – a behaviour that irrevocably separated humans from the rest of the animal kingdom.
Little did we know that chimpanzee tool use wouldn’t be the only discovery to make us gasp for air! Lacking any formal training in behavioural sciences, Dr Jane at the time had simply used her intuition to describe the personalities, feelings, and intentions of the Gombe chimpanzees. This was not at all appreciated by the male-dominated science field who, at the time, agreed that such things either did not exist or were impossible to study, and thus outside of academic interest.
It took decades for supporting scientific evidence to accumulate. To this date, we have learned that chimpanzees do in fact have personalities, feelings and intentions – Dr Jane was right! We’ve also learned so much more; the emotional need of chimpanzees to reconcile after disputes 1,2. We have learned about their tactical choices of allies 3, their aggression and warfare 4,5. We have learned that they know what others know and intend 6, and thus can cooperatively hunt 7 and solve problems 8, comfort 1, deceive 9 and teach each other 10, 11. We have learned that they plan for the near future 11. We have learned that while some chimpanzees successfully invent novel solutions to everyday problems 12, others can learn from them by just watching 13.
Take the cracking of hard-shelled nuts with a stone or wooden hammer and an anvil. This behaviour must have been invented by a chimpanzee a long time ago in the Tai Forest in Cote d’Ivoire, and has subsequently been passed on to others. Today, at least three Tai groups crack open nuts 14, but this behaviour is entirely absent at other places 15, 16.
Moreover, there are group-specific differences on how the nuts are cracked open 17. Early in the season, when the nuts have comparatively soft shells, wooden hammers are used by two of the groups. They switch to stone hammers in the course of the nut season when the shells get harder. However, in one group, stone hammers are used throughout the year – although stone hammers are rare in the territories of all three groups. Interestingly, females who transfer from one group to the next at puberty, have been observed to adapt to their new group. They switch from the behaviour of their natal group, for example, using only stone hammers, to the behaviour of their new group, like using wooden and stone hammers.
Today, as more and more chimpanzee communities are studied in the wild, we just start to get a first glimpse of their rich cultural diversity. This gets us back to termite fishing: when Jane first observed David Greybeard fishing for termites at Gombe 63 years ago, she did not know that termites are an important source of protein to many – but not all – chimpanzee groups throughout Africa.
In the meantime, we have learned that different chimpanzee groups used different termite fishing techniques 18. Some of these differences are firmly rooted in ecology, while others seem to be culture-bound. For example, some termites live in aerial mounds, while others live in underground mounds. While the termite soldiers living in the aerial mounds can be made to bite with a single stick, two sticks, which are used one after the other, are needed to access the termites living in underground mounds at other places. Thus, the techniques necessary to access the termites living in these two mound forms depend on an ecological difference.
However, fishing for underground termites alone can take several different forms, and these seem to be group specific. While the Goualougo chimpanzees sit while they fish for underground termites, the Wonga Wongue chimpanzees lay on their sides. Yet the Korup chimpanzees lay on their sides and lean on an elbow. It is hard to think that these differences in body postures are rooted in ecological differences in the places where these chimpanzees reside. Rather, it’s very likely to reflect the extent to which our closest relatives in the animal kingdom learn from each other and pass over their specific cultural behaviours from one generation to the next, just as we do. The wild chimpanzees living in the forests and savannas in Africa will continue to do so and steadily develop their very own cultures well into the future – if we let them do so.
Join us in celebrating chimpanzees this World Chimpanzee Day
Reach out to your local Roots & Shoots or Jane Goodall Institute office to find out how to support local initiatives in chimpanzee conservation