Today’s Animal World: Our Co-Inhabitants will be presented in Japanese, with subtitles in Arabic, Aulacese (Vietnamese), Chinese, English, French, German, Indonesian, Italian, Japanese, Korean, Malay, Mongolian, Persian, Portuguese, Russian, Spanish and Thai.

Graceful viewers, welcome to Animal World: Our Co-Inhabitants. Today’s show is the first in a two-part series where we explore the intelligence of chimpanzees and their sophisticated social structures with Dr. Tetsuro Matsuzawa, director of Kyoto University’s Primate Research Institute in Inuyama City, Japan.

He has spent over three decades studying wild chimpanzees and made significant discoveries regarding their abilities and skills. He has published many books and papers based on his findings. Dr. Matsuzawa is also known for pioneering a new field of research called “comparative cognitive science” which involves studying chimpanzees for clues as to how human intelligence and behavior evolved over time.

The chimpanzee is the most intimate being, and can be called an evolutionary neighbor for a man. If we can understand a chimpanzee well, we can also understand animals other than human beings.

For his important research work on chimpanzees, Dr. Matsuzawa received the Prince Chichibu Memorial Science Award in 1991, the Jane Goodall Award in 2001, and the Medal with a Purple Ribbon from the Japanese government in 2004. Let us now learn more about his study of these primates in Africa.

We hear that you go to Africa every year. And you are also studying the social behavior of wild chimpanzees. First of all, please explain to us their family structure and how they live in the forests.

Chimpanzees live only in Africa. They exist nowhere else but the equatorial forests of Africa and areas of savanna surrounded by these forests. Their habitats are distributed widely from Tanzania in the east to Guinea or Senegal in the west. Their family or their society is mostly made up of tens of chimpanzees or sometimes over a hundred. So they live together in groups.

The group consists of multiple male and female adult chimpanzees, and of course their children. Male baby chimpanzees stay among the group all their lives. But female chimpanzees leave the group or transfer to the next or nearby group whenever they reach adulthood or enter puberty and are ready to give birth. We call it a paternal society meaning a society built on fathers.

We are beings with 98.8 % the same genome. Our common ancestor existed maybe about six million years ago. But since about six million years ago, a man evolved into a man, and a chimpanzee evolved into a chimpanzee.

Similar to human beings, chimpanzees living in different areas may experience unique conditions and surroundings and thus acquire specialized or different knowledge and skills. Scientists also believe that the development of some abilities are not connected with the environment and are culturally learned behaviors. For example the chimps living in Bossou, Guinea in Western Africa, like their counterparts living in other places, use leaves to quench their thirst by placing them inside a tree hole and letting them soak up the water inside.

However only the Bossou chimpanzees have been seen folding the leaf in their mouth to create a small vessel and then placing the tool into the water source. Other behaviors thought unique to the Bossou chimps include feeding on algae by skimming the surface of ponds using the stem of a fern or other plant and then placing the stem in their mouth.

We hear that a chimpanzee is intelligent enough to use tools like a man. Would you enlighten us with what kind of tools they are using and what for with an example? v Chimpanzees are known for using various kinds of tools, but the important thing is that they use a unique tool based on their own cultural heritage that vary according to each area. For example, what I have been studying is chimpanzees living around a small village called Bossou in Guinea, Western Africa. They use a set of stones: one as a base and the other as a hammer to crack hard seeds of palm trees.

This is a palm. Press it a little, won’t you? (Yes.) It’s hard, isn‘t it? We cannot eat it like this. But when cracked, open, seeds or nuts like almonds are inside. Chimpanzees crack the hull using a hammer and a base and then eat the nuts. These are the tools that they are actually using: a hammer and a base. They get on a stone or a base like this. This is a stone hammer. They have been using it again and again for generations, so there is a dent on the surface. This stone is heavy. Just check the weight.

Oh, it’s heavy, isn’t it? I notice the dent on the surface.

They crack the hull and take the nuts out and eat it. This is the most famous tool used by chimpanzees in Bossou.

A team of archaeologists led by Julio Mercader of the University of Calgary in Canada found stone hammers used by chimpanzees living 4,300 years ago in an area that is now a part of the modern-day African nation of Cote-d'Ivoire. Their research concluded that the practice of using these tools to crack nuts was not the result of imitating humans, but rather something independently discovered by the primates, with the knowledge then being passed down through the generations to the present day.

This palm seed doesn’t seem edible by itself. Nobody knows we can eat the inside and that there are nuts inside. But when parent chimpanzees are cracking the hull, baby chimpanzees stare at it, and the knowledge that “there are nuts inside this seed, and when cracked by using a set of stones: a hammer and a base, the nuts inside are edible” as well as the technique itself has been passed to children from their parents for generations.

And what is interesting is that parents do not teach, they just show how to do it. Child chimpanzees watch and learn by observing. We call this “without teaching” or “learning by watching.” In English it is called “education by master- apprenticeship.” This is a way of learning where a student or an apprentice views how a mother or a master is doing something for a long period of time and learns it by watching.

Active teaching means teaching by using hands and directing by oral language. There is no active teaching among chimpanzees.

So I think in the case of transmitting traditional skills to successors or for posterity, “education by a master” or apprenticeship, what these chimpanzees are doing, is probably the most basic form of transmitting traditions for posterity.

Through his research, Dr. Matsuzawa also found that wild chimpanzees living in Bassou have learned to recognize and deactivate complex snare traps set by humans without injury. This behavior has kept the Bassou population relatively safe from these hazards. In other chimpanzee communities where this knowledge is lacking, sadly some members have been severely hurt by the traps.

Our research group has just recently reported that chimpanzees can dismantle traps set up by humans.

The trap is not set up for a chimpanzee, but for a smaller animal like a rat. There are snare traps to catch them throughout Africa. A looped wire is wound on the end of a bowed stick, and when a small animal steps on the stick, its spring makes the wire bind tightly around the object. A hand or a leg of a chimpanzee is trapped by such a snare trap. And the snare trap used to be made of a vine, so even if a chimpanzee was trapped, escape was possible.

But nowadays it is made of a wire, thus it won’t decompose. Chimpanzees keep losing fingers or toes because of tightly binding traps. These incidents have been happening all over Africa. Chimpanzees of Bossou know the shape of a snare trap, and adult chimpanzees smash down the trap because the knowledge and skill to dismantle the trap have been transmitted for generations just as in the case of transmission of tradition and culture.

As I have mentioned before, cultural tradition varies according to regions, and a child watches and imitates what parents are doing. You can consider the behavior of dismantling a trap as a variation of using various kinds of tools.

Wow, how smart they are! Our admiring big hug, sweet and clever chimps! And our gratitude Dr. Tetsuro Matsuzawa, for sharing your insightful research that is helping many more people appreciate the intelligent and loving nature of our chimpanzee friends and other animals as well.

Lovely viewers, please join us again next Thursday on Animal World: Our Co-Inhabitants when Dr. Matsuzawa will introduce more of his fascinating findings as we further explore the beautiful emotional and intellectual worlds of chimpanzees.

For more details on Dr. Matsuzawa, please visit

We enjoyed your company today on our program. Coming up next is Enlightening Entertainment after Noteworthy News. May Earth’s inhabitants always live with love and respect for each other.