Evolutionary Anthropology 19:205–209 (2010)
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The XXIIIrd Congress of the International Primatological Society: An Increasingly Globalized and Holistic Primatology—Japanese-style
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he 23rd Congress of the International Primatological Society (IPS) was held this year from September 12–18 in the city of Kyoto, a checkerboard of contrasting tall modern buildings, orderly gardens, ancient royal dwellings, beautiful temples, and Shinto shrines. Bounded between two rivers, Kyoto is surrounded on all sides by forested hillsides still populated by indigenous Japanese macaques. The events of the Congress were, most appropriately, held at the University of Kyoto, a birthplace of modern field primatology. For anyone interested in this history, there was an extensive display of Kinji Imanishi’s original field notebooks and other artifacts of his wide-ranging career (Fig. 1). It was Imanishi who, in 1948, first went to Koshima Island and, together with his students, Shunzo Kawamura and Jun’ichiro Itani (whose battered binoculars were also on display) (Fig. 2), worked out the elaborate matrilineal social organization of macaques and, as it turned out, almost all cercopithecine monkeys.1 In the ensuing years, Itani and colleagues (Toshisado Nishida, Jiro Tanaka, and Yukimaru Sugiyama) fanned out to Africa and India to study monkeys and great apes, including humans still living as foragers. The aim of these Japanese pioneers was to attain an understanding of the roots of humanity by studying the diversity of primate behaviors from multiple perspectives, including psychological, ecological, and cultural. This holistic tradition continues to flourish in Japan, as illustrated by Takeshi Furuichi’s superb plenary talk on 30 years of research among wild bonobos in the Congo, together with the many papers presented by other faculty and students from the Primate Research Institute (PRI). At the PRI, under the directorship of Tetsuro Matsuzawa, longterm African ape field research is
complemented by equally ambitious research in comparative cognitive development and neuroscience, as well as by conservation programs like Support for African/Asian Great Apes (SAGA). Decades later, these state-ofthe-art programs remain true to Japanese primatology’s unique integrative vision. One memorable moment occurred during lunch, when Matsuzawa patiently explained to some of us what is meant by the Japanese concept of ‘‘kokoro,’’ a peculiarly comprehensive term for ‘‘mind’’ that incorporates knowledge, emotion, and will. The Congress allowed many non-Japanese primatologists to savor the scientific products of Japan’s active network of primatologists and meet many of them in person both as scientists and gracious hosts. The roles of culture and socialization in learning to understand and empathize with animals were vividly brought home in Alison Jolly’s historical tour through children’s books featuring ani-
mal characters, including her own recent books designed to introduce school children in Madagascar to their country’s unique natural history. The audience’s affection and reverence for this pioneer in the study of primate cognition, lemur social organization, and conservation was palpable. All members rose to give Jolly a standing ovation as President Juichi Yamagiwa presented her with the Society’s Lifetime Achievement Award (Fig. 3). In keeping with the Japanese emphasis on mechanisms that sustain social living, the Congress in Kyoto stood out because greater attention than in years past was given to ‘‘prosocial’’ aspects of primate life. In the opening session, Sarah Hrdy (University of California, Davis) set the stage by asking what happens when apes adopt cooperative breeding with alloparental care and provisioning of young. In a carefully crafted argument, Hrdy offered her answer: Apes develop to care more about the men-
Figure 1. Shunzo Kawamura’s field notes encompass his broad range of interests from animal ecology and behavior to ethnography. Photo courtesy of S. Hrdy. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]
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Figure 2. Jun’ichiro Itani’s battered binoculars. Photo courtesy of S. Hrdy. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]
tal states and feelings of others. This is accompanied by directional selection favoring those individuals that are good at engaging with others in this way. One of the critical mechanisms supporting this ability was described in a fascinating presentation by Giacomo Rizzolatti (University of Parma, Italy) on mirror neurons, which provide the neural substrate for empathetic understanding of the intentions of others. First discovered in macaques, then confirmed in humans, this neural capacity has now been documented in some birds. In a later talk by Hecht (Emory) and colleagues, evidence was presented that the human mirror neuron system is constructed to pay attention to both the method and the purpose of actions of others, whereas nonhuman primates may attend only to the purpose. Along with these plenary talks, there were sessions on ‘‘Caring for Others,’’ chaired by Cronin (University of Wisconsin, Madison) and Campbell (Emory); ‘‘Social Affiliation and Stress Regulation,’’ chaired by Polizzi di Sorrentino (Liverpool John Moores University) and Newton-Fisher (University of Kent); and ‘‘Reciprocity in Great Apes,’’ convened by Hare (Duke University) and Yamamoto
(Kyoto City Zoo) with the aim of exploring the diversity of opinions on ‘‘the cognitive skills in orangutans, chimpanzees and bonobos related to maintaining reciprocal relationships’’ —and diverse they were. Complicating the interpretation of these studies is the realization that the subjects used in experiments are highly intelligent, resourceful, and complicated creatures, each with its own personal history; for instance, Proctor and Brosnan (Georgia State) showed that chimpanzees can use turn-taking reciprocity, but may reserve it for particular partners which might or might not happen to be the ones chosen by researchers. These sessions occurred side by side and, unfortunately, often overlapped with presentations of more conventional, but increasingly fine-grained studies of parental and alloparental behavior, which range from something very close to allomaternal teaching among the tamarins studied by Rapaport (Clemson) to nursing behaviors by grandmothers in the galagos studied by Nash and Kessler (Arizona State). Altogether, we came out of the Congress impressed with the emerging evidence of extensive cooperative and other behaviors designed to increase
the benefits or mitigate the costs of social living. Other plenary highlights included a lucid summary by Gen Suwa (University of Tokyo) of the importance of Ardipithecus ramidus in understanding the evolution of the hominid lineages. Even by 4.5 mya, Ardipithecus showed some bipedal features, reduced canine dimorphism, and adaptations to woodland ecology. In his plenary speech, Bernard Thierry (Strasbourg University) reminded a large audience that social behaviors, like morphology, can be constrained by phylogenetic history or pleiotropy, so that some aspects of social structure may not evolve quickly in response to changing ecological conditions. Literally last, but not least, IPS President Juichi Yamagiwa’s (Kyoto University) closing plenary talk emphasized the theme of this conference, coexistence between human and nonhuman primates, illustrating it with a vivid account of changing relationships between the Japanese people and Japanese macaques.
EVOLUTIONARY HIGHLIGHTS OF CONTRIBUTED PAPERS AND SYMPOSIA As is typical of major research conferences, this Congress offered far more intellectual stimulation than any normal human could possibly take in. With nearly 800 spoken papers and 134 posters crammed into five days of up to eleven concurrent sessions, we could only taste a fraction of what was offered; our impressions are necessarily biased, then, by what we were able to attend. Overall, the conference stood out for the very high ratio of new information per talk, as well as the increasing reliance on hypothesis testing. For example, the 1989 prediction by Tom Wynn and Bill McGrew that all the behaviors evidenced in Oldowan technologies would be shown to be within the range of other Great Apes, came up smelling like a rose after the session on Primate Archeology. Meanwhile, widely accepted hypotheses such as the expensive tissue hypothesis were challenged, in this case by Navarrete, Isler, and van Schaik
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Figure 3. Alison Jolly receiving a bouquet from Takayo Soma dressed in a kimono decorated with hand-painted Lemur catta individuals from Berenty Reserve. Photo courtesy of R. Mittermeier. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]
(Zurich), who summarized data on organ masses in 31 primate species and 130 other mammals that failed to show the predicted negative correlation between brain size and intestine mass. It is encouraging that some hypotheses can begin to be rejected, although active debate on this one is sure to continue for some time. In other realms, intriguing but conflicting evidence was presented. For instance, the hypothesis that the balanced polymorphism underlying color vision capacities in New World primates and some diurnal lemurs is adaptive was tested across a variety of species. In some species, including tamarins and squirrel monkeys, for-
aging trichromats did better overall than did dichromats, even if dichromats might have an edge in detecting and capturing camouflaged insects. In spider monkeys, however, Hiramastu (University of Tokyo), winner of this year’s Takashima Prize from the Primate Society of Japan, showed that trichromats did no better than dichromats in detecting and ingesting ripe fruits, despite the obvious color differences of ripe fruits. This lack of trichromatic advantage occurs apparently because luminance (achromatic) differences during ripening serve as adequate cues for fruit detection and selection at short distances.
If the 2008 Edinburgh meeting of the IPS was noteworthy for all the new information on colobines, the one in Kyoto stood out for its focus on the behavior and ecology of apes. This accent is perhaps not surprising, given the long history of Japanese studies on great apes and the fact that this is the 50th anniversary year for Gombe. A whole afternoon was devoted to retrospective analyses of questions that benefit from such a long-term perspective: male life histories and strategies, disease epidemics, slow changes in home range size and location, the rise and fall of social groups, and the effects of paternal versus maternal kinship on social relationships. Gombe, however, is only one of many long-term studies on apes now reaching or exceeding 20 years (for example, those in progress at Mahale, Kibale, Wamba, and Khao Yai). Many of these sites were prominently featured in Congress talks. Foreshadowed in previous conferences, further evidence emerged here that gibbon monogamy is competitive and facultative, with males competing for female attention, coexisting with rival males when territories with females are so scarce that they have to be shared. Many papers focused on the cognitive abilities of apes relative to each other and to humans. One symposium, hosted by Furuichi and Hashimoto (Kyoto University), summarized new behavioral and ecological evidence on wild bonobos and chimpanzees, with further analysis of implications for the evolution of their distinctive social organizations. Another symposium, hosted by John Herndon (Emory), compared chimpanzee and human differences in brain structure, social cognition, patterns of reproduction, and aging, both physical and cognitive. Other symposia and papers examined ape capacities relevant to the acquisition of cumulative culture, including the ability to imitate, innovate, accept novel foods, adopt ‘‘majority’’ rules, and tolerate close proximity of role models or naı¨ve individuals. Diverse papers compared social cognition in nonhuman primates (mostly chimpanzees and rhesus macaques) and humans, finding evidence of human specialization, even in young chil-
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dren, with respect to representing the beliefs of others, spontaneous helping of others without reward, and third-party punishment. Several memorable novelties were reported at the Congress. In an intriguing study, Mukhopadhyay and Sinha (National Institute of Advanced Studies, India) reported on frequent female (as well as male) emigration in a supposedly female-bonded cercopithecine, the bonnet macaque. Testing the idea that human hunting can rapidly select against conspicuousness, Papworth (Imperial College London) and colleagues showed that recent differences in hunting pressures were related to profound effects on the vocal behavior of two populations of titi monkeys living only 30 km apart. Surbeck (Max Planck) and colleagues provided the first direct evidence of maternal support in increasing male reproductive success in wild bonobos. Polizzi di Sorrentino (University of Parma, Italy) and colleagues provided the first solid evidence of postconflict reconciliation in a captive New World primate (Cebus apella), highlighting the puzzling absence of reports of such behavior in the wild. Increased interest in how group members reconcile conflicting interests to preserve group cohesion was evident in two distinct symposia, one on group coordination of travel, hosted by King (Zoological Society of London) and Sueur (University of Strasbourg) and another on group spatial foraging, hosted by Crofoot (Smithsonian Tropical Research Institute) and Janson (Montana). In both theoretical models and practice, individuals with the most to gain are often found to lead group progressions, although such initiative does not guarantee that the rest of the group will follow. Socially high-ranking individuals are more likely to lead progressions, perhaps because they are more likely to derive disproportionately high benefits from reaching the next resource. At the level of group spatial foraging, a variety of studies on species as different as capuchins and lemurs showed that groups prefer and remember areas or individual resources of high productivity. Several studies independently showed that groups avoid areas of recent use and may
even use species-specific patterns of fruit ripening to modulate returns to an area. Simultaneous monitoring of movements by several neighboring groups revealed subtle patterns of avoidance and area-restricted dominance in both capuchin monkeys and baboons. An important feature of some group movements is the avoidance of areas of high predation risk; how this risk is integrated into group coordination is still unknown. As at Edinburgh, only more so, conservation figured prominently. About a fifth of all contributions touched on conservation issues. Understandably, most of these papers concentrated on status reports and practical measures needed to sustain dwindling primate populations, including the recently recognized importance of avoiding disease transmission from humans to nonhuman primates. Of greatest evolutionary concern was new evidence that many populations and even entire species of apes, particularly gibbons, are under increasing threat of extinction. Just as we are starting to learn something about their behavioral flexibility in the wild, our chances of obtaining a sampling of the full range of their behaviors or even understanding their phylogeny may be stymied by the loss of study populations. Evolutionary perspectives can also help inform conservation strategies. For instance, declines in standard measures of genetic diversity can be sensitive markers of habitat fragmentation, even in small species with high population densities such as mouse lemurs, as shown by Radespiel (University of Veterinary Medicine, Hannover) and colleagues, as well as in large species with very large home ranges, such as the snubnosed monkeys studied by Liu (Chinese Academy of Sciences) and colleagues. Understanding life histories can be critical to conservation efforts. Preventing hunting may be even more important than habitat protection for slow-reproducing primates like the snub-nosed monkeys studied by Jin and Long (The Nature Conservancy, China) and the bonobos discussed by Hart (TshuapaLomami-Lualaba Project) and colleagues. A sad fact revealed by numerous studies is that bushmeat
hunting inside ‘‘protected’’ areas is common and highly detrimental to primate populations unless strong legal and enforcement measures are adopted. In several reports across a wide array of primates, behavioral flexibility was found to allow populations to adapt to novel, degraded, or agriculturally modified habitats and thus buffer the impacts of habitat disturbance.
METHODOLOGICAL ADVANCES At this Congress, various methodological advances were showcased, each of which will increase the power of researchers to measure social, ecological, and genetic features of primate populations. For instance, the emerging power of modern genetics to address evolutionary questions was featured in several symposia and papers. Evidence from sequence variation near suspected sites of selection allowed Kawamura (University of Tokyo) to demonstrate that strong balancing selection is maintaining the peculiar polymorphism of color-vision alleles in New World monkeys and lemurs. In contrast, the possibility that gene loss may have significantly contributed to human evolution was discussed in the symposium led by Satta (The Graduate University for Advanced Studies, Sokendai). In a symposium hosted by Lynch Alfaro (University of California, Los Angeles), molecular taxonomy was strongly featured in resolving the confusing species groups of capuchin monkeys in Central and South America, leading to suggestions of considerable revision of current classifications. Similar insights concerning origins and relationships among species and populations were found for tarsiers, gibbons, and orangutans. In a symposium hosted by Blair (Columbia), Guschansky (Imperial College London), and Melnick (Columbia), combining the power of genetics, spatially explicit modeling, and landscape genetics was discussed as a powerful tool to investigate both historical and actual patterns of gene flow. A possible refinement for the study of social structure was demonstrated in a symposium on Social Network Theory and Analysis, hosted by Lauren Brent, Julia Lehmann, and
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Stuart Semple (Roehampton University). This field recognizes that social interactions are rarely only dyadic, but that existing tools, such as matrices of agonistic or affiliative interaction frequencies, tend to bias or force our perspective into a pair-wise analysis of social data. In contrast, network analysis provides extended measures of interactions that take into account more complex possible relationships, such as the degree to which an individual interacts with many or few other group members and the extent to which their interactions are concentrated on a few or many partners. In principle, network analysis can be used to combine structural information from quite distinct behaviors, contexts (for example, agonism, affiliation, and food versus mating), or time periods to generate an overall ‘‘picture’’ of social structure and provide a single measure of social complexity. A novel prediction from network theory is that when a social system is perturbed, the response of the system will occur in the subset of interactions for which the networks are least constrained and will tend to reduce the uncertainty individuals face about their social context. In the analysis by Lusseau (University of Aberdeen) and colleagues, changes in the agonistic structure of a group provoked notable and predictable changes in the affiliative structure (grooming, proximity). In other analyses, some network metrics correlated well with certain reproductive outcomes, while others seemed to reflect ecological changes across seasons or years. An open question, raised by one of the participants in the audience, is whether these network metrics, as opposed to more traditional measures of rank, tolerance, kinship, and proximity, provide intrinsically different information or are simply a different way to reflect these basic variables. Another area of rapidly growing advances is the use of indirect or noninvasive measures of basic quantities of interest to the evolution of primate behavior. A prime example is indirect measures of energy balance, the subject of a symposium hosted by MacLarnon and Ross (Roehampton University) as well as several other papers presented at the
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Congress. Because these measures indicate either hormonal correlates of stress or byproducts of metabolism, their interpretation is not always obvious, but in practice there are usually clear correlations between the measures and independent measures of food scarcity or nutritional stress. In a workshop on innovations in field methods, Crofoot (Smithsonian Tropical Research Institute) demonstrated the use of GPS collars that allow the collection of absolute location and even limited behavioral data on animals that cannot easily be tracked on foot. Nishikawa (Kyoto University) and colleagues demonstrated the utility of GPS collars in an elegant foraging study of paired female Japanese macaques of different social ranks, showing how group members both avoid each other and converge in space, depending on food distribution. In a symposium on obtaining cognitive data from observations in the wild, Byrne and Bates (University of St. Andrews) hosted diverse talks making the point that much useful information about social and ecological cognition can be obtained from rigorous data across contexts in the wild, even when these are not strict experiments. Likewise, the hypothesis of social learning of cultural variants was supported by rigorous comparisons of behavioral variations in foraging and tool use among populations of orangutans in a study by Kru ¨ tzen (Zurich) and colleagues, as well as a study of chimpanzees by Luncz and Boesch (Max Planck). Expanding and supporting the ability of primatologists to devote time and effort to field studies was the focus of Caine’s (California State) well-attended session on the special dilemmas of balancing work and life, a first of its kind at IPS. The University of Mysore’s Professor Mewa Singh spoke forcefully about the need for policies like those recently adopted by the granting arm of the Department of Science and Technology of India, which take into account time off for family responsibilities. He also advocated their practice of allocating extra funds to hire research assistants for women field workers in traditional areas where it is considered unsuitable or unsafe for them to move about unaccompanied.
CONCLUSION This stimulating Congress showed increasing focus on hypothesis-testing, sophisticated modeling and statistical designs, incorporation of modern technologies for analysis of genetic variation, and advances in noninvasive or remote data collection. In a cultural shift, far less attention was given to documenting the costs of social living than to addressing how, either behaviorally or ecologically, group members can compensate for such costs. As long-term studies in many sites pass the 20-year mark, valuable information on lifetime reproductive strategies and success is emerging, even from the very long-lived apes. Conservation is becoming increasingly urgent, to the point that most field researchers must consider and implement practical conservation measures alongside rigorous science. A serendipitous side effect of the tendency of primatologists to establish their own study sites is the fact that each such site provides the potential for long-lasting protection of one or more primate populations as well as the chance to demonstrate the importance of nonhuman primates to the local populations that increasingly surround, and often interact with them. As a culture that has coexisted with wild and rural macaques for centuries, Japan was a most appropriate venue to explore these connections between human and nonhuman primates.
REFERENCES 1 Matsuzawa T, McGrew WC. 2010. Kinji Imanshi and 60 years of Japanese primatology. Curr Biol 18:587–591.
Charles Janson Division of Biological Sciences University of Montana Missoula, MT 59812 E-mail:
[email protected]
Sarah Hrdy University of California, Davis
C 2010 Wiley-Liss, Inc. V Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/evan20292
