Gombe Chimpanzee War

The Gombe Chimpanzee War, also known as the Four-Year War, was a violent conflict between two communities of chimpanzees in Gombe Stream National Park in the Kigoma region of Tanzania between 1974 and 1978. The two groups were once unified in the Kasakela community. By 1974, researcher Jane Goodall noticed the community splintering. Over a span of eight months, a large party of chimpanzees separated themselves into the southern area of Kasakela and were renamed the Kahama community. The separatists consisted of six adult males, three adult females and their young. The Kasakela was left with eight adult males, twelve adult females and their young.

During the four-year conflict, all males of the Kahama community were killed, effectively disbanding the community. The victorious Kasakela then expanded into further territory but were later repelled by two other communities of chimpanzees.

Background
Prior to the four-year war, before it became a national park, Gombe Stream National Park was known as the Gombe Stream Research Centre. The park is located in the lower region of the Kakombe Valley, and is known for its primate research opportunities first taken advantage of by researcher Jane Goodall, who served as the director of the Gombe Stream Research Centre. The site itself is composed of steep slopes of open woodland, rising above stream valleys lush with riverine forest.

The chimpanzees roamed across these hills in territorial communities, which divided the chimpanzees into parties ranging from one to 40 members. The term Kasakela refers to one of three areas of research in the central valley with the Kasakela in the north, the Kakombe, and the Mkenke to the south. Evidence of territorialism was first documented once Goodall followed the chimpanzees in their feeding situations, noting their aggressive territorial behavior. Chimpanzee males would patrol their territories and occasionally raid into the areas of other communities. However, violence during these patrols usually occurred in the form of attacks on isolated females and infants; the male patrols would mostly avoid each other or, if they met in equal members, limit themselves to noisy shows of force instead of seeking battle. Accordingly, Goodall did not foresee the upcoming full-scale conflict between two communities in Gombe.

The conflict began to emerge during the end of the tenure of Kasakela's long-term alpha, Mike. At this point, there were 14 adult males in the Kasakela community, and six of them increasingly spent time in the community's southern territory. Goodall and her colleagues began to refer to this section as the "southern sub-group", while the much more numerous remainder of the Kasakela was termed the "northern sub-group". Over several months, the males of the two sub-groups reacted with increasing hostility toward each other. The northerners initially avoided the southerners' areas, whereas the southern males, led by the brothers Hugh and Charlie, made forays into northern territory. The brothers were described as "fearless" by Goodall, and the northern males generally avoided confronting them. Despite the growing tensions, some peaceful contacts between the sub-groups were maintained by two older northern males, Mike and Rodolf, with a southern male, Goliath.

Two years after the sub-groups' emergence, the factions had developed into fully separate communities. The northern faction was now considered the Kasakela community, whereas the southern faction was termed the "Kahama community". At this point, the Kahama had given up the northernmost border areas of their range to the Kasakela, but the separatists still controlled an area where the Kasakela had previously "roamed at will". At this point, the two communities' patrols would make shows of force when encountering each other, though there was no open fighting. This situation continued for about a year. By 1974, the Kahama were still led by Hugh and Charlie, with the other males being Godi, De, Goliath, and the young Sniff. The Kasakela males included Satan, Sherry, Evered, Rodolf, Jomeo, Mike, Humphrey, and Figan, who had risen to dominant male.

War
First blood was drawn by the Kasakela community on January 7, 1974, when a party of six adult Kasakela males consisting of Humphrey, Figan, Jomeo, Sherry, Evered, and Rodolf ambushed the isolated Kahama male Godi while he was feeding on a tree. The Kasakela males were accompanied by one female, Gigi, who "charged back and forth around the melee". Despite Godi's attempt to flee, the attackers seized him, threw him on the ground and beat him until he stopped moving. Afterwards, the victorious chimpanzees celebrated boisterously, throwing and dragging branches with hoots and screams, and retreated. Once the Kasakela group had left, Godi stood up again, but probably died of his injuries soon after. This was the first time that any of the chimpanzees had been seen to deliberately attempt to kill a fellow male chimpanzee.

After Godi fell, the Kasakela ambushed and maimed De. In the attack on De, the female Gigi actually took part in combat alongside the Kasakela males. Just as in Godi's case, De was badly wounded in the assault and probably died soon after the clash. The third Kahama victim was the elderly Goliath. Throughout the leadup to the war and its initial stage, Goliath had been relatively friendly with the Kasakela neighbors when encounters occurred. However, his kindness was no longer reciprocated when a Kasakela patrol consisting of Figan, Faben, Humphrey, Satan, and Jomeo ambushed him. The researcher who observed this attack was shocked by the brutality and fury displayed by the Kasakela group, with Faben twisting Goliath's leg in a way as if he was trying to dismember it. The elderly chimpanzee probably died soon after the attack. Around this point, Hugh also vanished, with Goodall assuming that he too had been killed by the Kasakela. This left only three Kahama males: Charlie, Sniff, and Willy Wally, who was crippled from polio.

Charlie was the next victim. His death was not directly observed by the researchers, but fishermen reported hearing "sounds of fierce conflict"; three days later, his corpse was found with "terrible injuries" at the Kahama Stream. Next, the Kasakela chimpanzees attacked an elderly Kahama female, Madam Bee; she died of her wounds four days later. After Charlie's death, Willy Wally disappeared and was never found. The last remaining Kahama male, the young Sniff, survived for over a year. For some time it seemed as if he might escape into a new community or be welcomed back to the Kasakelas, but this did not occur. Sniff, too, fell to the Kasakela war band. Of the females from Kahama, one was killed, two went missing, and three were beaten and kidnapped by the Kasakela males. The Kasakela thus succeeded in taking over the Kahama's former territory, and spent the time after their victory moving through this area and feasting on its food sources. Temporarily, the community's territory increased from 12 to over 15 km2.

Aftermath
These territorial gains were not permanent, however. With the Kahama gone, the Kasakela territory now butted up directly against the territory of another chimpanzee community, called the Kalande. Goodall reasoned that the Kahama had functioned as a "buffer", and the Kalande now began expanding northward into Kasakela areas. Cowed by the superior strength and numbers of the Kalande, as well as a few violent skirmishes along their border, the Kasakela quickly gave up much of their new territory. They also lost at least two males, Humphrey and Sherry; presumably the two were killed by Kalande. Furthermore, when the Kasakela group moved back northward, they were harassed by foragers belonging to the Mitumba chimpanzee community, who also outnumbered the Kasakela community. Beset from north and south, the Kasakela territory shrunk to 5 km2 by 1981, an area barely able to feed the community's members.

In 1982, Kalande and Mitumba males invaded the Kasakela core area, and actually began to interact with each other. The Kasakela community's complete collapse was averted, however, as there was an unusual number of male young growing up in the community at the time. Though they were neither strong nor experienced enough to actually fight the Kalande and Mitumba, the Kasakela's young males could make noisy displays alongside the older males. This made it appear as if the Kasakela community was stronger than it actually was; this allowed the Kasakela to regain territory. Eventually, hostilities died down and the regular order of things was restored.

Effects on Goodall


Jane Goodall is known for her research on chimpanzees. The outbreak of the war shocked her, as she had previously considered chimpanzees to be, although similar to human beings, "rather 'nicer. Coupled with her 1975 observation of cannibalistic infanticide by a high-ranking female in the community, the Gombe war revealed the "dark side" of chimpanzee behavior. In her 1990 memoir Through a Window: My Thirty Years with the Chimpanzees of Gombe, she wrote: "For several years I struggled to come to terms with this new knowledge. Often when I woke in the night, horrific pictures sprang unbidden to my mind—Satan [one of the apes], cupping his hand below Sniff's chin to drink the blood that welled from a great wound on his face; old Rodolf, usually so benign, standing upright to hurl a four-pound rock at Godi's prostrate body; Jomeo tearing a strip of skin from Dé's thigh; Figan, charging and hitting, again and again, the stricken, quivering body of Goliath, one of his childhood heroes."

Legacy
When Goodall reported on the events of the Gombe War, her account of a naturally occurring war between chimpanzees was not universally believed. At the time, scientific models of human and animal behavior virtually never overlapped. Some scientists accused her of excessive anthropomorphism; others suggested that her presence, and her practice of feeding the chimpanzees, had created violent conflict in a naturally peaceful society. However, later research using less intrusive methods confirmed that chimpanzee societies, in their natural state, indeed wage war. A 2018 study published in the American Journal of Physical Anthropology concluded that the Gombe War was most likely a consequence of a power struggle between three high-ranking males, which was exacerbated by an unusual scarcity of fertile females.