by John Crocker
Male chimps learn display behaviors early in life by watching other males. Freud was only two when I saw him try to imitate seventeen-year-old Satan, who had just completed his maturation into adulthood. As Satan came thundering through our camp, hurling palm fronds and beating against a tree, chimps and researchers immediately moved aside. Young Freud watched quietly from behind a tree with Fifi. When all was clear and Satan long gone, Freud practiced his own display by trying to imitate Satan. With one-tenth the force, he gave a few soft pant-hoots, tossed some twigs in the air, wobbled as he stomped on the ground several times, and then quietly sat down. I think I was the only primate watching this attempt at a display, and I wanted to pretend for this earnest young chimp that I was frightened.
Actual physical fighting between males does take place, just as it can between young men or women. Male chimps fight to establish a social order, with a dominant male maintaining his position for up to several years before being dethroned. About half of male-male aggression is due to competition over status. Serious harm rarely occurs. The resultant pecking order serves to keep fights from occurring more often—usually around food sources and during mating. The hierarchy assures that each chimp knows his place. The alpha male may mate with a receptive female without having to fight off other males. Females seem to have a less defined hierarchy, but their strength and ability to defend themselves—even with an infant clinging to them—is impressive. There is only occasional fighting among female chimpanzees, sometimes over meat sharing or with immigrant females from a different community.
Still, a less aggressive male might consort with a female who is in estrus (sexually receptive). We jokingly called this “going on safari.” A quiet courtship develops, and the male seems to seduce the female (or vice versa) into traveling miles away from the community. After I departed, Caroline Tutin described Satan using sophisticated social skills, patience, and strategy to carefully lead Miff away from the group. The female’s mating exclusively with the lower-ranking male during that weeklong period widens the community’s gene pool. This non–alpha male accomplishment may also help to select for other inheritable traits, such as strategizing.
Apart from the sudden bursts of adrenaline that can trigger fight-or-flight with the enemy—snakes, buffalo, leopards, or other chimps from different communities—there’s a lot of downtime for the Gombe chimpanzees. They often rest by a stream or feed in a newly ripened fig tree for an hour or two. Even Figan did. As the alpha, he in particular needed to be able to pounce at any time. He could restore his calm almost instantly, however, by hugging another chimp for a few seconds or by prolonged grooming—in his case, usually receiving it. The social activity of grooming involves gentle touching and caressing. A chimp fingers through the hair of another chimp, appearing to search for bugs or burrs, though there are usually none to be found. It’s like back scratching and can occur in big groups or one-on-one. Groups of two to ten or more adult chimpanzees or a mother-infant pair will sit quietly and pick through each other’s hair in a very affectionate manner. In addition to being very relaxing and restorative, it appears to be a form of communication that strengthens the bonds of family and clan.
Physiologically, such calming behaviors provide a better balance for primates’ long-term health than does a constant hyped-up state. Studies in humans and other primates show that constantly circulating high levels of adrenaline and cortisol can weaken the immune system and cause long-term health problems such as fatigue, weight gain, digestive disorders, and depression. We’re only just beginning to understand the physiological effects of long-term stress on humans, but we know that a continuous state of stress is unhealthy.
Often in my practice I will see patients such as Maryann, who came to me with intestinal problems referred to as irritable bowel syndrome. In her case, we could trace the onset back to when her teenage son began acting out and having major problems in school. Although she assumed the cause of her constant abdominal discomfort was a bacterial infection, it improved as she sought medical help and psychological help to calm her constant worries and stress about her teenager.
Chimps in the wild appear to have developed other behaviors to alleviate stress as well. As a higher-ranking male traveling in the forest meets other males or females of the community, his hair becomes erect, sometimes triggering other males to display erect hair. As the highest-ranking male tenses with aggressive posturing, the others usually crouch and make soft grunting sounds of submission. This is followed by reassuring hugging, kissing, and eventual grooming, which quiet the heightened energy and soothe the group.
One day at Gombe I saw Fifi do something I hadn’t seen before: as her brother Figan was revving up for a display, rising onto his hind legs and with hair erect, Fifi reached from behind him and gently held his testicles with one hand. Figan immediately sat down, his pant-hoot softened, and he began to calmly groom himself. My field assistant, Yasini, placed a hand over his mouth to mute his chuckling at this scene. Just as grooming is reassuring and calming, Fifi’s gentle touch to Figan’s genitals pacified him and stopped an aggressive, tense display in its tracks.
This sexual calming strategy reminded me of bonobos, primate cousins to both chimps and humans. Formerly called pygmy chimpanzees, bonobos live in the south-central Democratic Republic of the Congo. They’re slightly smaller than chimpanzees and have less bulky bodies, more like ours. Bonobos use sex and sensuality to defuse aggression. They literally make love more than war. They use sex in a diverse way that extends far beyond mating. This includes males mounting males to dampen aggression, as well as two females rubbing together for friendly bonding. Neither of the latter behaviors results in orgasm. I recently became interested in this species when reading Bonobo Handshake. Author Vanessa Woods describes her growing love for these magnificent primates living in a sanctuary in Congo’s capital. Perhaps because of their specific rain forest habitat in the Congo Basin over millennia, they do not need the forceful protection and dominant displays of aggression required of the Gombe chimps to survive. Now their survival depends on an end to poaching and land destruction of their home in the rain forest.
Unlike chimpanzees, bonobos have a matriarchal society. But Jane Goodall has been quick to point out that even in the well-documented aggressive, patriarchal chimpanzee society, there are also examples of nurturing behavior by males. Gombe chimps Mel and Darbee were orphaned at age three-and-a-half, when their mothers died during a pneumonia epidemic. Each was subsequently adopted and cared for by young males in the community. Adolescent Spindle and young adult Beethoven, both of whom had lost their mothers, nurtured Mel and Darbee by sharing sleeping nests and attending to their daily needs. Interestingly, recent data on paternity (using DNA from feces samples) shows that Beethoven, who cared for Darbee, was actually her biological father. Although we don’t know enough about chimp DNA and hereditary behavior to draw hard conclusions about how fathers might identify with their offspring, it’s a fascinating piece of information.
Another example of male nurturing is documented in Chimpanzee, filmed in an African rainforest. This film highlights the true story of Freddy, an alpha male chimp who adopted and cared for Oscar, whose mother had died. Even the most powerful male chimpanzees are apparently capable of nurturing young chimps and providing care for them.
At Gombe, I was fortunate to be in the company of Richard Wrangham, who studied male behavior in chimpanzees and then later in his life became a MacArthur fellow and professor of human evolutionary biology at Harvard. Richard coauthored with Jane’s biographer, Dale Peterson, a moving and highly relevant book, Demonic Males: Apes and the Origins of Human Violence. He described how the males in our society have inherited aggression and violence from our chimp-like ancestors five million years ago. Although these genes are no longer needed for human survival today, their presence can cause major upheavals in male-dominated societies.
Modern humans might benefit from organizing our societies more like that of our bonobo rela
tives, who project more sexual equality and less aggression. Our bigger brain size and moral code become crucial for our future survival and must be used wisely as they compensate for our “demonic” tendencies. From my own observations of male chimpanzee behavior in the wild and from Richard’s in-depth analysis, I began to understand the reasons for aggression and competition in the chimps’ world. This in turn helped me better understand these behaviors in my own species.
CHAPTER FIVE
MADAME BEE HOLDS HER OWN
About three months after my arrival, I woke up before dawn one morning, threw on khaki shorts and shirt, tested my tape recorder, and headed to the beach camp. After tea and toast, I hiked a short distance to the field assistants’ quarters to meet Esilom, my assistant for the day. With a full moon to light our way, we strolled along the beach in companionable silence, passing three valleys before arriving at Kahama Valley, where the “southern” community of chimps lives.
Earlier in the week, one of the field assistants, Rugema, had announced to Jane and a few of us students, “I spotted Madame Bee and her new infant traveling in Kahama Valley, very close to our southern border.” Madame Bee was a mature chimp who was rarely seen in Kasekela Valley, where Fifi and her community roamed. Madame Bee was part of the southern Kahama community that had split off from the larger northern Kasekela group a few years earlier.
When Jane heard the news of the birth, her face lit up. Then she paused, turned to me, and asked, “John, how would you like to travel to the Kahama community to see how Madame Bee is doing with her new infant?”
Although this ambitious assignment surprised me because I was still a newcomer, of course I quickly agreed. Later that night I sarcastically quipped to my fellow researcher Caroline, “I did have to check my busy schedule before I gave Jane the OK.” This was definitely one of my more exciting fieldwork assignments, and anticipating my journey south to unfamiliar territory added suspense.
Jane’s attentiveness to my work was encouraging and exciting. Though she didn’t usually go with me into the field, we often talked in the evening about my observations. Rather than be overprotective of the process, Jane would turn the student researchers loose in the forest, trusting them to give her accurate documentation of the chimps they studied. I felt honored that she was allowing me to go follow Madame Bee.
Our early-morning walk along the beach was pastoral. The full moon still lingered, and all was quiet except for the lapping of waves on the lakeshore. We passed several fishermen’s small grass huts, which were deserted, as the fishermen never worked on a full moon. The men would sail out at night to catch small fish called degas with handmade nets, using lanterns to attract the fish to their boats; a bright moon would interfere with this technique. On this day, the men were with their families in the villages just over the mountains.
Esilom and I finally met up with Rafael, a guide who knew the southern community of chimps. We headed into the valley where the Bee family nested, looking for Madame Bee, who traveled with her infant, Little Bee, and her nine-year-old daughter, Honey Bee. It was important to find the chimps’ nests before they awoke and began to travel.
At our destination, I gazed up at the nest at sunrise. I felt a flash of insecurity, realizing that I was in an unfamiliar valley with a community of chimps I didn’t know. I felt a bit homesick for the chimps I’d grown to know in Kasekela Valley. Since researchers didn’t follow these southern chimps much, I was uncertain how they’d react to researchers trekking after them. Would they be frightened and flee, or become aggressive and possibly attack us?
As the sky lightened, a female chimp emerged from the nest, her infant clinging to her belly. “That is Madame Bee,” Rafael whispered. Bee’s older daughter, Honey Bee, had slept in her own nest, and she soon joined them. I felt a twist in my stomach when I saw that Madame Bee cradled her infant with just one arm while the other arm hung useless at her side. I made eye contact with Esilom; he nodded slightly. Madame Bee’s arm had been paralyzed during the polio epidemic that swept through the chimp community in 1966.
The illness most likely spread from people in a nearby village that had experienced an outbreak of polio just prior to its appearance in the chimps at Gombe. According to information released in 2005 by the National Human Genome Research Institute (NHGRI), human DNA is 96 percent identical to chimpanzee DNA, so it’s not surprising that chimps can catch many illnesses from us—everything from common colds to polio, measles, MRSA (methicillin-resistant Staphylococcus aureus), and other bacterial, viral, and parasitic infections.
As I observed her, however, I was happy to see that Madame Bee could swing through the trees with one functional arm, moving slowly and carefully, as Little Bee clung to her belly. I was impressed with how this mother chimp had adapted to her life. It was an inspirational sight—a chimp whose disability did not prevent her from doing her job as a mother. Soon after birth, infant chimps are able to cling to their mother’s torso hair and remain safely attached to her belly as she travels through the forest. This is certainly good for survival, as it frees up both of the mother’s hands for traveling and the arduous task of building a nest high in the trees while her infant remains securely tucked underneath her. Even so, I couldn’t imagine how Madame Bee built a nest with one arm while caring for Little Bee at the same time. As Madame Bee fed on milk apples, Little Bee nursed and Honey Bee explored the ground below. I sat, quietly taking in the views of enormous leafy trees and vines and listening to a multitude of animal sounds.
I was jolted out of my reverie when loud pant-hoots and screams suddenly started coming from higher up the valley. The Kahama males, who had nested a hundred yards away, had awakened and were journeying through the forest.
The noise grew even louder, and I gripped my notebook. Branches thrashed, and then, just fifty feet away, three male chimps charged straight at us. I realized I didn’t know which males were dominant in this community, and my panic intensified. I was crouched and ready to head in the opposite direction for safety, but Esilom moved up next to me and said softly, “We’re OK here.”
The commotion was residual excitement over a colobus monkey kill the day before. Each of the three males had caught a colobus, and one of them, Godi, was displaying his catch by waving the carcass. I knew the difference between the play face—open mouth and relaxed lips—that chimps make when playing with each other, and the aggressive grimace, teeth flashing, made during charges. What I saw wasn’t play faces.
At one point I thought things were calming, but I was wrong. Godi’s display was still building as he flung branches and stampeded across the ground, screaming loud pant-hoots, his hair fully erect. Then there was a few minutes’ respite as he resumed eating more of the colobus carcass. Other chimps sat nearby, begging for scraps of meat.
Just as I was hoping the show was over, the lead male, Charlie, arrived and the drama escalated. Females screamed. The earth shook. My two field assistants and I tried to shrink into the background so we wouldn’t become targets. There were only seven adult males, but it seemed like twenty.
As Charlie approached, all the males began to display again. Then Godi and another male, Sniff, suddenly turned on Madame Bee, who had retreated up a tree. To my shock, the large chimps hit her and eventually pushed her and Little Bee out of the tree. There was no clear reason for this attack other than to show off their power. I grew angry watching poor Madame Bee scream and try to protect herself and Little Bee as they crept along the ground. They escaped from the commotion a bit shaken, but uninjured. Madame Bee, Little Bee, and Honey Bee finally stopped screaming but stayed very close to one another while grooming, eating fruit, and traveling after that.
Meanwhile, the males and a few females in the group scaled a huge cliff by grabbing hold of dangling vines to hoist themselves up. Esilom and I stayed with the Bee family as they traveled slowly on level terrain, with Rafael helping us navigate the unfamiliar valley.
I was quite shaken by the male violence. Watching a
disabled mother chimp assaulted with such force was deeply upsetting. Perhaps the reason for this attack was hardwired into these primates’ survival instincts. I thought about the inescapable fact of human aggression. Bullying came to mind. These chimps were our closest primate relatives—the most like our own species. Their violence was staggering and extremely frightening, like similar kinds of human behavior—rampages, unprovoked attacks, and the strong who single out the weak for violence—what we too often see on the nightly news. Perhaps we haven’t evolved as much as we would like to believe.
In marked contrast to the male displays of power, it was soothing to observe the calm mother-infant relationships, like those of Madame Bee and her daughters. Most mother-infant pairs spend the majority of their time in relaxed and peaceful encounters, such as grooming, playing, and foraging. I had time to watch Madame Bee with her infant and see how her older daughter, Honey Bee, helped from time to time by grooming her mother. Honey Bee’s real motive, though, seemed to be trying to get closer to her infant sister, as she constantly reached over to gently touch Little Bee. Honey Bee would even sniff the ground where her little sibling had sat, as if she were programmed to recognize even the scent of her infant sister. The intimate interactions and communications between these family members may have been one of the reasons Madame Bee could successfully raise her offspring in the wild even with her disabled arm.
By midafternoon, I decided to leave Rafael and Esilom and head back to Gombe on my own. Slated for duty at the camp medical clinic, I wanted to take a dip in the lake before my shift. I arrived at our makeshift one-room medical clinic in time to help during doctors’ hours, then joined the other researchers for dinner at the dining hall, where I found out I was expected to give an account of my trip to the southern community. Jane, Richard, Nancy, Caroline, and Bill were curious to hear about the Bee family and how Madame Bee was doing with her infant. Sitting at a large wooden table, I described the brutal attack on Madame Bee as everyone around the table shook their heads.