This installment of Discovering Us tells the story of an unusual group of chimpanzees that live on the grassy plains of Fongoli, Senegal where temperatures reach over 110 degrees. Water is scarce, and wildfires sweep through every year - burning the leaves from the trees and baking the soil. These chimpanzees have adapted to their environment in surprising ways that can shed light on the evolution of our own species.
This installment of Discovering Us tells the story of an unusual group of chimpanzees that live on the grassy plains of Fongoli, Senegal where temperatures reach over 110 degrees. Water is scarce, and wildfires sweep through every year - burning the leaves from the trees and baking the soil. These chimpanzees have adapted to their environment in surprising ways that can shed light on the evolution of our own species.
Further reading:
About The Leakey Foundation
The Leakey Foundation is a nonprofit organization dedicated to funding human origins research and sharing discoveries. The Foundation was established in 1968 to fund work at the forefront of fossil and primate studies and provide opportunities for a global community of scientists. Learn more at leakeyfoundation.org.
Discovering Us: 50 Great Discoveries in Human Origins
In 50 lively and up-to-the-minute essays illustrated with full-color photographs, Discovering Us: 50 Great Discoveries in Human Origins presents stories of the most exciting and groundbreaking surprises revealed by human origins research.
Prepared in consultation with leading experts and written by Evan Hadingham, senior science editor for NOVA, Discovering Us features stunning photographs, some taken at the actual moment that groundbreaking discoveries were made. The book presents a highly accessible account of the latest scientific insights into the ultimate question of humanity’s origins. Discovering Us was published by Signature Books.
Find Discovering Us at your local library, bookstore, or amazon.com.
Show Credits:
Discovering Us was made possible by generous support from Camilla and George Smith, the Ann and Gordon Getty Foundation, and the Joan and Arnold Travis Education Fund.
Meredith Johnson:
This is Discovering Us from The Leakey Foundation and Signature Books … an audio companion to the book Discovering Us: 50 Great Discoveries in Human Origins. Written by Evan Hadingham and read for you by Ashley Judd.
I’m your host, Meredith Johnson.
This installment of Discovering Us takes us to Fongoli, Senegal - where Leakey Foundation grantee and primatologist Jill Pruetz studies an unusual group of chimpanzees. Temperatures in Fongoli often reach over 110 degrees fahrenheit. Water is scarce, and each year, during the dry season, wild fires sweep through - burning the leaves from the trees and baking the soil. These chimpanzees have adapted to their environment in surprising ways. Ways that can shed light on the evolution of our own species.
Here’s Ashley Judd…
Ashley Judd:
Chimpanzee Hunting
At first, primatologist Jill Pruetz could hardly believe her research assistant’s report.
He had watched Tumbo, a female chimpanzee, strip the leaves off a small branch, trim one end to make a sharp point, and then use it like a spear to poke at a bush baby—a pocket-sized nocturnal primate—that lay sleeping in its nest in a hollow tree.
When Tumbo finally captured the bush baby, she bit its head off.
Southeastern Senegal lies at the far western extreme of chimpanzees’ range in Africa.
The landscape at Fongoli is mostly open, semi-arid grasslands with a few scattered trees. In 2001, with Leakey Foundation support, Jill Pruetz set up her study of a chimpanzee band in this harsh bushland, which teems with ticks, cobras, and black mamba snakes.
A lack of creature comforts is no obstacle to her. She has suffered a bout of tick fever and dug a botfly out of her foot, and she comes down with malaria nearly every year.
As Pruetz followed the Fongoli chimps around, she began noticing their unusual behavior.
Unlike most other chimp populations, they spend much of their time on the ground in a single, large communal group.
Most chimps are afraid of water, but at the peak of the summer heat, when temperatures often soar above a hundred degrees Farenheit, they soak in pools to cool off or take shelter in nearby caves.
During the full moon, they move around and forage at night.
These are remarkable observations, but the report of Tumbo’s spear hunting was stunning news.
No one had ever seen chimpanzees hunt with tools before, and in most other communities, dominant males lead the hunt - not females.
It soon became clear that the observation was no fluke.
In a 2015 study, Pruetz’s team documented more than 300 cases of bush baby spear hunting.
Females carried out more than half of these hunts and were the most avid tool makers and users.
When males did participate, they tended to wait for opportunistic moments, chasing down fleeing bush babies after they had been flushed out of their nests by females or juveniles.
What’s also interesting is that adult males tended to respect the ownership of the meat acquired by females, juveniles, or low-ranking males.
In other chimp populations, dominant males typically steal around a quarter of the kills made by others. At Fongoli, this happened in only five percent of the cases.
Why is there more social cohesion and tolerance among males at Fongoli than elsewhere?
Part of the answer is that males do their own hunting at Fongoli. As well as bush babies, they chase down other prey such as vervet monkeys and baboons that females, who usually have infants clinging to them, have little chance of catching.
The tree-bound bush babies, on the other hand, are a source of meat that females and young chimps can readily acquire with the aid of the tools they make.
Pruetz believes that another explanation lies in the relative sparseness of the semi-arid grasslands compared to the rainforest.
She says that “In the savanna, food sources are few and far between, which can exert pressure to make more sophisticated tools and develop more innovative hunting behaviors. We see it today with the chimps at my site, and hominins may have responded to this challenging habitat in the same way.”
The transition in East Africa around 2 million years ago, from a forested environment to a savanna resembling Fongoli today, is often held responsible for accelerating the pace of our ancestors’ tool use, social development, and growing brain.
Pruetz’s groundbreaking work at Fongoli shows how female inventiveness played a key role along the winding path that led to our humanity.
[MUSIC rises and then ducks under closing credits]
Discovering Us: 50 Great Discoveries in Human Origins was written for The Leakey Foundation by Evan Hadingham. It was published by Signature Books. The stories are read for you by Ashley Judd.
All the episodes of this audio-companion are available to listen to right now! Make sure to subscribe and share this series with a friend.
You can buy a copy of Discovering Us at your local bookstore or wherever you buy books. There’s a link in the shownotes.
The Leakey Foundation is a nonprofit organization dedicated to funding human origins research and sharing discoveries. The science you heard about today was made possible by Leakey Foundation supporters. Visit our website to learn how you can get involved. Go to leakeyfoundation.org. That’s l-e-a-k-e-y foundation dot org.
This project was made possible by generous support from Camilla and George Smith, the Joan and Arnold Travis Education Fund, and the Ann and Gordon Getty Foundation