He had long been interested in the standing of humans among the primates, and was dissecting baboons in South Africa while still a teenager.7 But he was not wholly unmoved by the plight of the hunted baboons, and later quoted this early-twentieth-century account:Hugging her baby tight to her breast, she regarded us with a world of sadness in her eyes, and with a gasp and shudder she died. We forgot for the moment that she was but a monkey, for her actions and expression were so human, that we felt we had committed a crime. Muttering an oath, my friend turned and walked rapidly off, vowing that this was the last time he would shoot a monkey. “It isn’t sport, it’s downright murder,” he declared, and I fervently agreed with him.8
If you wanted to meet a baboon—and you lived in a country where they didn’t roam about in the wild—you could always go to the local zoo and see the bedraggled and deracinated inmates, lifers pent up in tiny cubicles. After World War I, some European zoos thought it would be better, as well as more “humane,” if a large number of baboons could be gathered together in a partly open enclosure admitting observation by city-bound primatologists. The London Zoo was among them, and Dr. Zuckerman was playing a central role in the organization of one of these multiyear experiments:
In the spring of 1925, about one hundred hamadryas baboons were introduced into moat-bordered Monkey Hill, about 33 by 20 meters in area. So each baboon had, on average, less than 7 square meters, or some 60 square feet, indeed about the size of a small prison cell. It had been intended that this be an all-male group, but through an “accidental inclusion” six of the hundred baboons proved to be female. After a time, the oversight was rectified and the group was augmented by a further thirty females and five males. By late 1931, 64% of the males were dead, and 92% of the females:Of the thirty-three females that died, thirty lost their lives in fights, in which they were the prizes fought for by the males. The injuries inflicted were of all degrees of severity Limb-bones, ribs, and even the skull, have been fractured. Wounds have sometimes penetrated the chest or abdomen, and many animals showed extensive lacerations in the ano-genital region … The fight in which the last of these females lost her life was so protracted and repellent—from the anthropocentric point of view—that the decision was made to remove the five surviving females from the Hill … The very high percentage of females killed in the London Colony suggests. . that the social group of which they formed a part was in some way unnatural.9
Despite this last qualification, the hamadryas colony at the London Zoo reinforced a widespread belief in an unconstrained Darwinian struggle for existence. Even though baboons would quickly have exterminated themselves from the world if the events at Monkey Hill were characteristic of life in the wild, many people felt that they had now glimpsed Nature in the raw, a brutal Nature, red in claw and fang, a Nature from which we humans are insulated and protected by our civilized institutions and sensibilities. And Zuckerman’s vivid descriptions of the unrestrained sex lives of the baboons—he was one of the first to stress that baboon social organization may be determined largely by sexual considerations—increased the contempt that many humans felt toward the other primates.
What had gone wrong on Monkey Hill? First, almost all of the baboons introduced into the “colony” were unknown to one another. There was no long-term mutual habituation, no prior establishment of dominance hierarchies, no common understanding in these harem-obsessed males of who was to have many females and who none at all. No kinship-based female dominance hierarchy had been established. Unlike the situation in the wild, there were many more males than females. Finally, these baboons were crowded together to a degree rarely experienced in their natural state.
Because of their powerful jaws and spectacular canines, baboon males within a troop hardly ever fight among themselves in earnest, although corporal punishment is visited on the females for the slightest infractions. But in the London Zoo, dominance hierarchies had to be established, dedicated attempts were made to steal females, escape from a formidable attacker was cut off by the moat, and the calming influence of many sexually compliant females was almost entirely wanting. The result was carnage. In all six and a half years, only one infant survived. When the males would fight over them, the adult females would listlessly wait, as if “paralysed.” The battered, lacerated, punctured females would be sexually used by a quick succession of males.
But the females were not mere passive instruments:[W]hen her overlord’s back was turned she quickly presented to the bachelor attached to her party, who mounted for a moment. The overlord then slightly turned his head, whereupon the female rushed to him, her body low to the ground, presenting and squealing, and threatening her seducer with grimaces and with quick thrusts of her hands on the rocks. This behaviour immediately stimulated an attack by the overlord … Closely pursued, the bachelor fled. On another occasion the same female was left alone for forty seconds while her overlord chased a bachelor around Monkey Hill. In that space of time she was mounted and penetrated by two males to whom she had presented. Both of these immediately made off after their contact with the female, who again responded to the return of her male in the manner described above.10
When females were killed, the males would continue to drag them around, one male after another, to fight over them, and to copulate with their corpses. When the keepers, grimly watching this necrophilial tableau unfold, felt it necessary—for “anthropocentric” reasons—to enter the compound and remove the dead body, the males, in concert, would violently object and resist. Zuckerman, writing back then in the 1920s, used and may have coined the phrase “a sexual object”11 in describing the lot of the female baboon.
We’ve seen in Calhoun’s experiments with rats that—even when there’s plenty of food, even when there are as many males as females—severe crowding induces violent and other modes of behavior that many would describe as aberrant and maladaptive. We’ve also seen in the Arnhem chimp colony how, under similar circumstances, new modes of behavior come to the fore to inhibit violence. From the baboons in the London Zoo we learn that if you take a species given to sexual violence in the best of conditions, provide a small number of sexual prizes to be fought over, arrange to have no pre-existing social order in which the animals know where they fit, and now crowd everybody together with no hope of escape, mayhem is the likely outcome. Monkey Hill reveals a deadly intersection of sex, hierarchy, violence, and crowding that may or may not apply to other primates.*
In Nature, as Zuckerman recognized, hamadryas baboons live much more peaceably. Dominant males are surrounded by a small corona of females, their offspring, and a few affiliated “bachelor” males. These harems wander over the landscape in bands, collecting food. Hundreds of baboons, a kind of gathering of the tribes, camp out each night near one another on sleeping cliffs. Fights to the death for possession of the females (or for any other reason) hardly ever happen. Everyone knows his, and especially her, place. The females are of course routinely abused, bitten on average once a day, but not so deeply as to draw blood. They are certainly not all killed off because they might be interested in other males, as happened in the London Zoo.
Hamadryas baboons in very small groups behave very differently: A bachelor baboon male watches a couple—on their first date—in an adjacent cage. Days go by, and he is forced to observe their deepening sexual relationship while he sits alone. When he’s then introduced into their cage, he makes no effort to attack the male or to lure the female away. He respects their relationship. He looks away when they have sex. He is a model of rectitude and circumspection, even if he’s of larger stature than either.12