I remember the summer after my first year of graduate school vividly. There I was, in Kenya, following wild monkeys through the bush. Finally! It was a dream come true for me. I have loved monkeys for as long as I can remember. As a child, I played with monkey stuffed animals instead of dolls. In high school, my AP history teacher gave me an introductory textbook about anthropology and I was overjoyed to learn that I could study my favorite animals in college and beyond. Now, roughly five years later, I was intently observing a group of about 50 patas monkeys (Eyrthrocebus patas) as they searched for food, played, and groomed one another. Suddenly, one of the monkeys gave a loud, staccato vocalization that sounded like “Nyow!” Soon, other individuals joined in. There I was, in the middle of the group, taking it all in and loving every second of it. That is until my advisor slowly approached me and pointed to the grass on the edge of the group. “Look,” she said, “we need to go back to the car.” I looked closely in the direction she was pointing and saw, crouching in the grass, a large lion. We slowly backed away and walked to our car. Looking back, I should have been scared, but I wasn’t, I was thrilled. I would return a year later to study the same group’s response to predators for two years.
Nonhuman primates (hereafter, “primates”) are a fascinating group of animals, whose similarity to humans can be striking. Because of this similarity, studying primates helps anthropologists to gain insight into how our human ancestors may have behaved. It also allows us to better understand our own behavior through comparison (examining similarities and differences) with other primates as well as by comparing different species of primates to one another. In this way, studying primates helps anthropologists comprehend humanity from a biological perspective, which contributes to anthropology’s commitment to holism, the idea that the parts of a system interconnect and interact to make up the whole.
Ethology is the study of animal behavior, while primatology is the study of primate behavior. People who study primates are called primatologists. Research on primates can be conducted in the field (i.e., on wild primates) or in captivity (i.e., zoos) and may or may not involve experiments, such as playing recorded alarm calls to see how individuals react. Unlike some other Science, Technology, Engineering, and Math (STEM) fields, primatology has a long history of research conducted by women (see “Special Topic: Women in Primatology”). Primatologists come from many different disciplines, have diverse backgrounds, and study primates for different reasons. Biologists study primates as examples of evolutionary theories like natural selection, and to understand behaviors as adaptations, or traits with a function that increases fitness, i.e. an individual’s survival and/or reproduction. Primate intelligence is of interest to psychologists who want to learn more about deception or cooperation and to linguists interested in the principles of communication and language. Ecologists consider how primates interact with the habitats they occupy, and conservationists examine how primates are affected by deforestation, poaching, or illegal animal trade (see Appendix B: Primate Conservation for more information on these topics). Biological anthropologists, like myself (Figure 6.1), who study primates are interested in learning about their social complexity, and ecological and behavioral variation, to better understand the biological basis of human behavior. And, similar to biologists, we also explore how primate behavior is adaptive and contributes to individual fitness. Like other sciences, primatology is only as strong as its researchers, methods, and theories, and the field has benefitted recently from efforts to increase diversity and reckon with its colonialist past, as discussed below in “Special Topic: Women in Primatology.”
Humans share many traits in common with primates. As you learned in Chapter 5, some of these traits are similar due to homology, traits both species inherited from a common primate ancestor. For example, like most other primates, humans are social animals who live in groups. Group living did not evolve independently in humans and other primates. Rather, group living is a trait that evolved in a primate ancestor, and because it benefited survival, it was retained in the species’ descendants (or the species that come after the ancestor species). In contrast, humans and other primates can have similar traits that evolved independently, which is called analogy. For example, both humans and Japanese macaques (Macaca fuscata) use natural hot springs (Figures 6.2a-b). Research on these monkeys indicates that sitting in hot springs reduces stress and helps keep them warm, much as it does for humans (Takeshita et al. 2018). But this behavior is not the result of humans and Japanese macaques having a shared ancestor who used hot springs. Rather, the behavior arose independently in two species that both occupy northerly environments and adapted to cold climates using a similar behavior. Studying the homologous traits we share with other primates, like living in groups, helps us develop hypotheses about human behaviors as adaptations, which in turn helps us develop models for the behavior of our human ancestors. Studying analogous traits, like hot springs use, allows us to better understand the effects of ecological variables on morphology and behavior of both primates and humans, living and extinct.
Special Topic: Women in Primatology
While many STEM fields have traditionally been, and continue to be, dominated by men, primatology has a long history of significant research conducted by women. This is due, in part, to the fact that three of the most well-known primatologists are women. In the early 1960s, British paleoanthropologist Louis Leakey (discussed in Chapters 9 and 10) was looking for students to study the great apes in hopes of shedding light on the behaviors of our early ancestors. He chose Jane Goodall (Figure 6.3a) to study chimpanzees (Pan troglodytes), Birute Galdikas (Figure 6.3b) to study Bornean orangutans (Pongo pygmaeus), and Dian Fossey (Figure 6.3c) to study mountain gorillas (Gorillaberingei beringei). The work of these three women, sometimes referred to as Leakey’s “Trimates,” has transformed our understanding of ape (and primate) behavior.
Arriving at the Gombe Stream Reserve in Tanzania in 1960, Jane Goodall was one of the first scientists to conduct a long-term study of wild nonhuman primates. Before then, most studies lasted less than a year and were often zoo-based. By 1961, she had made two astounding observations that forced us to reconsider what differentiates humans from the rest of the primate order. She observed chimpanzees eating a colobus monkey, the first reported evidence of meat eating in our closest relatives (she later observed them hunting and sharing meat). And she discovered that chimpanzees make and use tools by stripping leaves off twigs to “fish” for termites. Her work, spanning several decades, has produced long-term data on chimpanzee mating strategies, mother-infant bonds, and aggression. In the mid-1980s, Goodall transitioned from field researcher to conservationist and activist, advocating for the humane use of nonhuman animals (Stanford 2017).
Birute Galdikas began her study of orangutans in Kalimantan, Borneo, in 1971. Hers was the first long-term study conducted on the Bornean orangutan. Galdikas and her colleagues have collected over 150,000 hours of observational data, focusing on the life histories of individual orangutans. While conducting behavioral research, Galdikas discovered that the pet trade and habitat loss were adversely affecting the orangutan population. Eventually, Galdikas’s conservation efforts began to extend beyond advocacy and into rehabilitation and forest preservation (Bell 2017). If you would like to learn more about primate conservation efforts, please see Appendix B: Primate Conservation.
In 1967, Dian Fossey began her long-term study of mountain gorillas and founded the Karisoke Research Center in Rwanda. Her and her colleagues’ research, over several decades, revealed much about gorilla social behavior, ecology, and life history. Her efforts also led to the development of mountain gorilla conservation programs. However, she was a controversial figure, as discussed below. Fossey was murdered in December 1985; the case remains unsolved (Stewart 2017).
Recently, the movement to decolonize primatology, by understanding and highlighting the theories and research of non-Western individuals and perspectives, has gathered steam. This movement draws attention to the maltreatment of local people by Western primatologists. For example, Michelle Rodrigues (2019) argues that it’s time we stop focusing on the scientific and conservation contributions of Dian Fossey and acknowledge that her “active conservation” techniques included kidnapping and torturing local Rwandans who were known as, or suspected to be, gorilla poachers. Rodrigues (2019) argues:
The image of Fossey, a white American woman, whipping and torturing black African poachers is evocative of the behavior of white slaveholders in the American South. It is appalling enough to think of that behavior occurring in the 1850s; there is no way we can explain Fossey’s behavior in the 1970s as the product of “a different time.” Yet, almost three decades later, the romantic notion of a noble martyr who died for her devotion to gorillas prevails, and these terrifying actions are often described as simply unorthodox methods. Perhaps these truths are softened due to fears that the reality of this legacy would harm gorilla conservation efforts. But memorializing her as a martyr and patron saint of gorilla conservation demands that we forget the cruel acts she advocated for and performed.
Further, Louis Leakey’s installment of Goodall, Galdikas, and Fossey to study chimpanzees, orangutans, and mountain gorillas, respectively, is itself viewed as recapitulating the colonial legacy in Africa and Asia. Given that Leakey was the offspring of British missionaries, Rodrigues (2019) argues, it is no accident that he was willing to mentor British and American women, while overlooking women from Africa and Asia as potential researchers. This leads us to another level of the decolonizing movement, which aims to highlight the research of non-Western primatologists, particularly those living in what primatologists refer to as “habitat countries” that are home to living primates. As you will see in this chapter, scientists from diverse backgrounds are active contributors to exciting research on primates around the world.