This sort of behavior catches visitors’ eyes. “They’re playing,” I heard one father mutter when confronted with the sight of 16-year-old Vic assuming the missionary position for sex with one of the young females. “No. They’re making babies,” someone in his family retorted, eliciting giggles. “They’re mating!” one of the kids blurted out.
When 18-month-old Kakowet arrived at the Children’s Zoo in the summer of 1960, primatologists knew almost nothing about the eccentricities of bonobo sexual practices. Only one other zoo outside of Africa claimed any bonobos at that point; the facility in Frankfurt, Germany, had a pair. Kakowet was the first bonobo to survive in North America, and for more than two years, his only companions were some of the other young primates (gorilla, chimpanzee, orangutan) also housed in the Children’s Zoo. In October of 1962, however, the director of the Antwerp Zoo in Belgium shipped a special gift to San Diego: a six-year-old, 46-pound female bonobo named Linda. She and Kakowet soon became the only breeding pair in the Western Hemisphere. Over the next 18 years, they produced 11 offspring, a feat unmatched by any bonobos in the wild, where females typically give birth only every four or five years. But with her babies whisked off to be bottle-fed in the nursery here, Linda would quickly begin to ovulate again.
Loretta, the couple’s fifth baby, was born on January 22, 1974. At 43, she’s the reigning matriarch in the colony today. Because much of her head is bald, zoo visitors often mistake her for an aging male. “But the reason she’s bald is because she’s very popular. She gets groomed a lot,” one of Loretta’s fans told me.
Although the San Diego Zoo may do almost nothing to publicize its bonobo colony, the rare apes command a small but ardent group of devotees. Liz Sauer is one of them. A mutual friend put me in touch with her, and Sauer agreed to meet with me at the bonobos’ enclosure. A San Diego native, she was taken to the zoo while growing up but says she didn’t know anything about bonobos until she was a student at UCLA. There she took a psychology class that included some discussion of our primate relatives.
In the class, Sauer learned about their unusual sexual conduct. “It’s very casual,” she commented. “It alleviates a lot of conflict, and it’s also about bonding and affection.” She found that interesting, and the bonobos’ avoidance of killing their fellows struck her as being even more intriguing. “That’s unheard of in primates. It kind of gives me hope for humans. We look at the chimpanzee model of our evolution and think we’re destined to be this warlike culture that fears outsiders.”
Researchers have demonstrated, however, that bonobos are more likely to share food with other bonobos who are strangers than they are with acquaintances.
“In the wild, if a group comes upon another group of bonobos, they’ll engage in a lot of sexual behavior, and then they’ll share food and groom each other,” Sauer said. Bonobos are more likely to yawn when confronted by the sight of an unfamiliar bonobo yawning than they are by a yawning acquaintance. Contagious yawning is considered to be an indicator of empathy. “They call them xenophilic. They’re welcoming of strangers,” she said. “They’re more willing to share with strangers than with their own group.”
Sauer nonetheless didn’t realize the San Diego Zoo was home to a colony of bonobos until recently. “I loved the zoo and have been a member for a long time, but you kind of tend to follow a certain path that you always take.” Her routine was to stroll by the gorillas and then down to the aviary, then go through it to see the pandas, followed by the polar bears. Only about a year and a half ago, when Sauer was at the zoo with a friend and her two-year-old, did a volunteer suggest they shouldn’t miss seeing the baby bonobo. Sauer and her companions found their way to the exhibit. “Mali came up and made eye contact with me,” Sauer recalled, “That was it for me.”
Sustained eye contact makes most animals uncomfortable. Dogs avoid it. So do gorillas. “But bonobos will gaze into your eyes,” Sauer said. “It’s so intense; it’s like they’re looking into your soul. They’re completely focused on you. When you first make that connection, it’s like a drug.”
Once exposed to them, Sauer resolved to learn as much as she could about bonobos. She obtained a copy of Frans de Waal’s Bonobo, The Forgotten Ape. A world-renowned primatologist, De Waal began his groundbreaking studies of bonobos in 1983 at the San Diego Zoo, which then housed the world’s largest captive bonobo colony (ten members divided into three groups).
“I spent entire days in front of the enclosure with a video camera,” he wrote in a 2006 article in the journal Evolution. De Waal soon distinguished more than 50 behavior patterns, many of them relating to sexual interactions. He concluded that while chimpanzees (“the Machiavellis of the primate world”) resolve sexual issues with power, bonobos resolve power issues with sex.
Before his observations in San Diego, “I had heard that bonobos were sexy,” De Waal wrote in The Forgotten Ape, “but I was nonetheless amazed by the sheer variety of positions and the extent to which the apes mutually stimulated one another. “He concluded that “bonobos have more ways of inviting each other sexually, more ways of engaging in sex, and more different facial expressions and vocalization associated with sexual intercourse than chimpanzees.”
While the chimps’ sex life “is rather plain and boring, bonobos act as if they have read the Kama Sutra,” De Waal reported. Females have loud and enthusiastic orgasms. Tongue-kissing among both species is commonplace. (Based on hundreds of hours of watching bonobos, De Waal added the qualifier that “their sexual activity is rather casual and relaxed…. Like people, bonobos engage in sex only occasionally, not continuously. Furthermore, with the average copulation lasting 13 seconds, sexual contact in bonobos is rather quick by human standards.”)