Six Chimpanzees, Three Monkeys, One Afternoon at Gombe
A Lesson in Chimpanzee Hunting
On the afternoon of March 19, 1974, I struggled through the dense forest of upper Mkenke valley trying to keep up with Yahaya Alamasi and the six chimpanzees we were following. When I finally caught up with them beside the stream, all six sat silently staring into the canopy.
Somewhere above us, hidden sixty to eighty feet overhead, red colobus monkeys barked alarm calls while branches crashed and leaves shook.
In less than fifteen minutes, three monkeys would be dead.
Only once before had chimpanzees been seen killing more than one monkey in a single day.1
The prevailing view held that chimpanzees hunted cooperatively and then gathered to share the spoils. What Yahaya and I witnessed that afternoon suggested a more complicated reality.
Caroline Tutin, Yahaya Alamasi, and David Riss (photo 1973 by Emilie van Zinnicq Bergmann-Riss).
Why This Day Mattered
On October 30, 1960, Jane Goodall watched a male chimpanzee she later named David Greybeard eating fresh meat from the carcass of a young bushpig. The observation challenged the prevailing scientific belief that chimpanzees were strict vegetarians. Five days later, David Greybeard would provide another surprise by fashioning a twig to extract termites from the ground.
During the following decade, Jane and her students learned that although meat made up only a tiny portion of the chimpanzees’ predominantly fruit-based diet, it appeared to be their favorite food.
Researchers observed chimpanzees opportunistically killing piglets and young bushbuck, and actively hunting young baboons near the banana-provisioning station. By the end of the 1960s, the accepted picture was clear: chimpanzees often hunted cooperatively and shared the meat.
Gigi feeds from the remains of a bushbuck fawn stolen from baboons (background). I saw old Mike (right) at several kills; this was the only time he failed to take control of the carcass. 
That picture began to change in the early 1970s.
Banana provisioning had been drastically reduced, and students increasingly followed chimpanzees away from the feeding station and into the forest. There, they discovered that the chimpanzees’ preferred prey was not baboons at all, but red colobus monkeys.
These monkeys typically lived high in the forest canopy, often in groups of thirty to fifty individuals including multiple adult males. Hunting them required considerable skill. Chimpanzees had to pursue lighter and more agile prey through the treetops while risking falls and counterattacks from protective adult male monkeys.
Adult male red colobus monkeys could be quite fierce (in Swahili: “kali sana“) (Shutterstock/Robin Nieuwenkamp). See Day 27 of the Figan Follow.
During 1973 and 1974, David Riss and I followed adult male chimpanzees at Gombe for a total of 1,830 hours. We saw them hunt red colobus monkeys twenty-four times (once every 76 hours). Eleven of those hunts were successful (46%), yielding fourteen kills.
Most of the hunting was by groups of two or more males. Typically, once a monkey had been caught, the excitement shifted immediately to the carcass as chimpanzees begged, competed, and even fought for meat.
But not always.
March 19, 1974
On this day, Yahaya and I were following Humphrey and Evered, who joined up around noon with four other adult males: Figan, Satan, Jomeo, and Sherry.2
By early afternoon the group had entered a densely forested region of upper Mkenke valley near the Mkenke stream, about one hundred yards upstream from the tallest waterfall at Gombe (video, below).
The Mkenke waterfall is the tallest at Gombe — approximately 85 ft. high (July, 2024).
The understory was thick from the rainy season. While the chimpanzees and Yahaya moved easily through the tangled, thorny vegetation, I was still learning the art of moving through the forest and quickly fell behind.
Eventually I caught up with them beside the stream. All six chimpanzees sat quietly on the ground, staring into the canopy downstream. Yahaya stood nearby.3
Only then did I register the sounds overhead: chirping calls, crashing branches, and movement high in the trees.
“Chiondi,” Yahaya said, using the local word for red colobus monkeys.
I caught fleeting glimpses of monkeys running along branches and leaping through the treetops. The chimpanzees watched for several minutes. Then everything exploded.
Red colobus monkey leaping, Uganda. (Shutterstock/Daniel Lamborn)
Humphrey, Figan, and Satan rushed downslope along the stream and climbed into the trees. Yahaya followed immediately. Once again, I became entangled in thorny vines. Fortunately for me, Evered and the brothers Jomeo and Sherry had stayed behind.
Ahead of us, hidden by vegetation, came the sounds of chaos. I briefly saw Figan charging along the ground, shaking branches before disappearing from view. A few minutes later Yahaya returned with exciting news. He had seen Figan carrying a small piece of fresh meat and suspected that Humphrey had already made a kill. How Humphrey caught that monkey, however, he didn’t know.
At that moment our attention shifted to far overhead. Sherry raced along a branch pursuing a mother carrying an infant on her belly. After a brief chase, the monkeys escaped.
Mother and infant red colobus monkeys in Uganda. (Adobe Stock/Sascha)
Meanwhile, Evered and Jomeo remained below, watching. Then, with Sherry still in the canopy, the two larger males climbed into the trees. Evered chased a different mother-infant pair but failed to close the distance.
For several minutes all I could make out were fleeting glimpses of chimpanzees through the understory, punctuated by monkey barks and crashing branches overhead.
Then Evered came into view just as he grabbed a mother, who bit him on the wrist. Evered screamed, ripped the infant from her belly, and disappeared into the foliage carrying his prize.
Barely a minute later came another commotion. Out of nowhere, a juvenile-sized monkey landed on the ground only a short distance from Yahaya and me. Jomeo was in hot pursuit. The monkey ran perhaps ten feet before freezing. Jomeo scooped it up and disappeared uphill, never to be seen again that day.
Not long afterward, Evered emerged carrying the dead infant monkey in his mouth. He walked directly past us and continued upstream, away from where Humphrey had gone.
Sherry followed briefly and begged for meat, but Evered ignored him. Within minutes Sherry had resumed hunting.
Rather than follow Evered or Jomeo, Yahaya and I went to search for Humphrey. Pant-hoots and screams led us directly to him. About eighty yards downhill, Humphrey sat ten feet up in a tree eating a juvenile monkey.
Adult male Sheldon with the remains of an adult colobus monkey at Gombe in 2024.
Nearby were Figan, Goblin, Patti, Athena, Atlas, and Dove. Some possessed scraps of meat. Others begged persistently for handouts.
More chimpanzees arrived, no doubt attracted by the excitement. Two hours later, almost all of the carcass had been eaten, much of it by Humphrey.
What March 19 Revealed to Me
First, chimpanzee hunting can be extraordinarily difficult to observe. Even experienced observers like Yahaya missed key events. We inferred that Humphrey made the first kill because Yahaya saw Figan carrying a small amount of fresh meat and we later found Humphrey in possession of an almost complete carcass. The details of the actual capture were unknown.
Madam Bee and Little Bee (climbing) watch colobus monkeys during a prolonged unsuccessful hunt by the Kahama community chimps on August 26, 1974. Arboreal hunting is largely a male activity — but not always.
Second, group hunting did not necessarily mean teamwork. Were Evered, Jomeo, and Sherry coordinating their efforts by cutting off escape routes and driving monkeys toward one another?
Or were they simply individual hunters taking advantage of the confusion and weakened defenses created by multiple simultaneous attacks? From our obscured position on the forest floor, we could not say with any confidence.
Third, a successful kill did not necessarily end the hunt. If Evered and Jomeo knew that Humphrey had already secured a monkey, they nevertheless chose to continue hunting rather than seek meat from him. Sherry continued hunting after begging unsuccessfully from Evered.
This differed from most prior observations in which chimpanzees stopped hunting and converged on a carcass once a kill had been made. Observers inevitably focused their attention there as well. Had I stayed with Humphrey, rather than lagging behind with Evered and Jomeo, the latter two kills would probably have gone unnoticed.
Finally, when making a kill, chimpanzees attempted to avoid the attention of others so far as possible (Wrangham, 1975).
Hunting Alone
March 19 raised another possibility: perhaps group hunting was not always necessary at all.
Only nine days later, on March 28, Yahaya and Yassini watched Figan hunt and kill a red colobus monkey entirely by himself. He consumed the carcass alone without attempting to recruit other chimpanzees.
I witnessed precisely the same result on July 10, when Sniff successfully hunted a colobus monkey while alone and quietly consumed the meat over several hours.
Sniff slowly and quietly eats a colobus monkey that he caught while hunting alone on July 10, 1974.
These observations demonstrated that group hunting was not required for successful predation, at least for some individuals.4 5
And when solitary hunters succeeded, they did not advertise their good fortune.
Conclusion
By 1974, the prevailing view held that chimpanzees hunted cooperatively and shared the spoils.
Our observations did not overturn that picture, but they complicated it. Chimpanzees sometimes hunted alone. Even when hunting in groups, successful captors such as Evered and Jomeo occasionally ran off with their kills rather than recruiting others to share the meat. Most telling of all, they remained quiet, making no attempt to advertise their success.
Chimpanzees predominantly hunt in groups, but determining the extent to which they deliberately coordinate their efforts remains challenging. Observers on the forest floor rarely have a complete view of activities occurring high in the canopy.
The events of March 19 shaped my understanding of chimpanzee hunting as something more flexible and nuanced than I had previously imagined: an opportunistic activity involving a complex mixture of individual initiative and occasional teamwork.
Curt Busse
June, 2026
Google Earth video showing the location of the March 19, 1974 hunt. Recorded on June 9, 2025, the video provides a reasonable approximation of the landscape and vegetation as I remember them more than fifty years earlier.
Sources and Further Reading
Van Lawick-Goodall, J. (1968). The Behaviour of Free-Living Chimpanzees in the Gombe Stream Reserve. Animal Behaviour Monographs, 1(3), 161–311.
van Lawick-Goodall, J. (1971). In the Shadow of Man. Boston: Houghton Mifflin Company.
Teleki, G. (1973). The Predatory Behavior of Wild Chimpanzees. Lewisburg, PA: Bucknell University Press.
Wrangham, R.W. (1975). The Behavioural Ecology of Chimpanzees in Gombe National Park, Tanzania. Ph.D. dissertation, University of Cambridge.
Busse, C.D. (1978). Do Chimpanzees Hunt Cooperatively? The American Naturalist, 112(986), 767–770.
Goodall, J. (1986). The Chimpanzees of Gombe: Patterns of Behavior. Cambridge, MA: The Belknap Press of Harvard University Press.
- As reported by Richard Wrangham (1975), Jane Goodall’s field assistant Esilom Mpongo and Park Warden Rweyongeza Mwenera observed the young adult male Sniff capture an infant red colobus monkey from its mother on September 11, 1973. The mother remained nearby and was killed by chimpanzees shortly afterward (page 4.13).
↩︎ - This was a powerhouse lineup of hunters, listed here in order of dominance rank:
1 — Figan (age 21)
2 — Evered (age 22)
3 — Humphrey (age 28)
5 — Satan (age 19)
6 — Jomeo (age 18)
7 — Sherry (age 14)
Not present at this hunt:
4 — Faben (age 27)
8 — Mike (age 36)
9 — Hugo (age 38)
↩︎ - Wrangham (1975) reported that chimpanzees were more likely to hunt red colobus monkeys where the forest canopy was broken and provided fewer escape routes. He highlighted the importance of emergent trees, especially Albizia sp., whose sturdy branches gave chimpanzees an advantage over the more agile monkeys.
David Riss and my observations generally fit this pattern. We saw multiple hunts and kills in mixed woodland-forest with broken canopy. Unfortunately, during the chaos of March 19, I was paying more attention to the chimpanzees than to the trees and made no notes on the structure of the canopy or the presence of emergent trees.
↩︎ - The first recorded observation of a chimpanzee hunting and killing a colobus monkey entirely on his own was made by William C. “Bill” McGrew, who watched Satan seize an infant from its mother on November 16, 1973. The mother’s screams apparently attracted nearby chimpanzees including Mike, who arrived soon afterward and siezed the carcass from Satan.
In a previous incident, Satan was entirely alone when he caught two piglets. He quietly consumed the prey by himself (Wrangham, 1975).
↩︎ - Busse (1977) reported 19 hunts from 1973 and 1974 in which the hunter was alone or with non-participating females. Six of these were successful: one by Satan, one by Figan, and four by Sniff (Kahama).
↩︎