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Novels about great apes and humans continue to be consistently popular with the reading public, sometimes reaching best-seller status. Media reviews of these books rarely comment on their primatological roots, nor do primatological journals review them. In a non-quantitative, pilot study, I scrutinize six prominent novels, in terms of three questions: How do the novels make use of primatology? What aspects of primatology do they use? How accurate is their use of primatology? Such novels overwhelmingly concentrate on language, with intelligence and sexuality lagging far behind; other topics, such as culture or technology, receive little or no attention. Apes in nature are rarely mentioned. Inaccuracies abound, even at the most basic level of primatological knowledge that easily could be remedied. Both authors and primatologists would benefit from more informative interaction before publication.

Cumulative culture, generally known as the increasing complexity or efficiency of cultural behaviors additively transmitted over successive generations, has been emphasized as a hallmark of human evolution. Recently, reviews of candidates for cumulative culture in nonhuman species have claimed that only humans have cumulative culture. Here, we aim to scrutinize this claim, using current criteria for cumulative culture to re-evaluate overlooked qualitative but longitudinal data from a nonhuman primate, the Japanese monkey (Macaca fuscata). We review over 60 years of Japanese ethnography of Koshima monkeys, which indicate that food-washing behaviors (e.g., of sweet potato tubers and wheat grains) seem to have increased in complexity and efficiency over time. Our reassessment of the Koshima ethnography is preliminary and nonquantitative, but it raises the possibility that cumulative culture, at least in a simple form, occurs spontaneously and adaptively in other primates and nonhumans in nature.

This work was supported by a research grant to K.J.H. from FCT, Portugal (PTDC/CS-ANT/121124/2010) and from MEXT, Japan (CCSN/PWS-U04). We are in a new epoch, the Anthropocene, and research into our closest living relatives, the great apes, must keep pace with the rate that our species is driving change. While a goal of many studies is to understand how great apes behave in natural contexts, the impact of human activities must increasingly be taken into account. This is both a challenge and an opportunity, which can importantly inform research in three diverse fields: cognition, human evolution, and conservation. No long-term great ape research site is wholly unaffected by human influence, but research at those that are especially affected by human activity is particularly important for ensuring that our great ape kin survive the Anthropocene. Postprint

Findings from field primatology show that three living primate genera—ape (Pan), Old World monkey (Macaca), and New World monkey (Sapajus)—use elementary lithic technology to obtain and process food in nature. All three taxa use stone tools, producing enduring artifacts with distinctive archaeological signatures. In a comparison we show that each taxon has its own suite of tools, both organic and inorganic. All use percussion, but there are differences in the number and type of other tools in each taxon. Our assessment also allows for point-by-point comparisons with the early toolkits of extinct hominins, and here we compare to the Oldowan. This broader comparison shows that modeling the evolutionary origins of human material culture continues to advance. Wynn’s “ape adaptive grade” must now be expanded to a more inclusive “simian adaptive grade,” as monkeys too show convergent features with percussive stone technology.

Extant non-human primates are our closest living relatives and knowledge of their diets serves as a focus for hypotheses about past diets. We now know that the diets of extant primates vary from almost total folivory to considerable faunivory. Subsistence strategies of extant primates and stable isotope ratio data constrain dietary scenarios for fossil primates, including hominins. Among extant primates, significant faunivory occurs only in species of 1 kg body weight, smaller primates feed on fruit or fruit with insects, and larger ones on fruit and foliage, including leaves, pith, stems, flowers, and bark. Fossil hominins fall into the size range for fruit and foliage-eating.

We describe behaviors of unhabituated wild chimpanzees in Gabon during repeated encounters with large mirrors installed permanently in their home range. Movement in proximity to the mirrors triggered video cameras that recorded the scene. Data are presented for 51 mirror encounters spanning a 3-year period. After initial wariness, mirror-directed aggressive behaviors were common, especially in adult males, but aggression gradually diminished and eventually almost completely ceased. Focusing on the two mirrors that elicited most reactions, the percentage of chimpanzees showing tension or anxiety also decreased across encounters. These mirrors elicited a range of socio-sexual behaviors interpreted as having a reassurance function, especially when group-level tension appeared high. Chimpanzees also occasionally directed these behaviors towards their own reflection. Despite increasing habituation and positive attraction to the mirrors, none of the chimpanzees displayed signs of self-recognition. We conclude that a combination of large mirrors and video traps can provide valuable information about unhabituated, semi-terrestrial primates in their natural habitat, by inducing the primates to stay in one place for longer than they might otherwise do.

Field studies done over decades of wild chimpanzees in East, Central and West Africa have yielded impressive, cumulative findings in cultural primatology. Japanese primatologists have been involved in this advance from the outset, over a wide variety of topics. Here I review the origins and development of field studies of Pan troglodytes, then assess their progress based on analogy between cultural primatology and cultural anthropology, through four stages: natural history, ethnography, ethnology, and intuition. Then, I focus on six topics that continue to yield informative debate: technology, universals, nuanced variation, archaeology, applied primatology, and ecology. Finally, I offer a map of sites of field study of wild chimpanzees. It is clear that Japanese primatologists have made a significant contribution to East-West scientific exchange, especially at the field sites of Bossou and Mahale.

Producing single versus multiple births has important life history trade-offs, including the potential benefits and risks of sharing a common in utero environment. Sex hormones can diffuse through amniotic fluid and fetal membranes, and females with male littermates risk exposure to high levels of fetal testosterone, which are shown to have masculinizing effects and negative fitness consequences in many mammals. Whereas most primates give birth to single offspring, several New World monkey and strepsirrhine species regularly give birth to small litters. We examined whether neonatal testosterone exposure might be detrimental to females in mixed-sex litters by compiling data from long-term breeding records for seven primate species (Saguinus oedipus; Varecia variegata, Varecia rubra, Microcebus murinis, Mirza coquereli, Cheirogaleus medius, Galago moholi). Litter sex ratios did not differ from the expected 1:2:1 (MM:MF:FF for twins) and 1:2:2:1 (MMM:MMF:MFF:FFF for triplets). Measures of reproductive success, including female survivorship, offspring-survivorship, and inter-birth interval, did not differ between females born in mixed-sex versus all-female litters, indicating that litter-producing non-human primates, unlike humans and rodents, show no signs of detrimental effects from androgen exposure in mixed sex litters. Although we found no evidence for CYP19A1 gene duplications-a hypothesized mechanism for coping with androgen exposure-aromatase protein evolution shows patterns of convergence among litter-producing taxa. That some primates have effectively found a way to circumvent a major cost of multiple births has implications for understanding variation in litter size and life history strategies across mammals.

[original article] Pan Africa News 26(2): 19–20 (2019): http://hdl.handle.net/2433/245545

Since its inception, archaeology has traditionally focused exclusively on humans and our direct ancestors. However, recent years have seen archaeological techniques applied to material evidence left behind by non-human animals. Here, we review advances made by the most prominent field investigating past non-human tool use: primate archaeology. This field combines survey of wild primate activity areas with ethological observations, excavations and analyses that allow the reconstruction of past primate behaviour. Because the order Primates includes humans, new insights into the behavioural evolution of apes and monkeys also can be used to better interrogate the record of early tool use in our own, hominin, lineage. This work has recently doubled the set of primate lineages with an excavated archaeological record, adding Old World macaques and New World capuchin monkeys to chimpanzees and humans, and it has shown that tool selection and transport, and discrete site formation, are universal among wild stone-tool-using primates. It has also revealed that wild capuchins regularly break stone tools in a way that can make them difficult to distinguish from simple early hominin tools. Ultimately, this research opens up opportunities for the development of a broader animal archaeology, marking the end of archaeology's anthropocentric era.

Inclusion of osteological material in primatological research has a long history, and use of skeletal remains continues to be important in anatomical and anthropological research. Here we report a set of proven methods, including equipment, protocol, and procedure, which enable relatively simple acquisition of skeletal material from naturally deceased animals in field sites and sanctuaries. Such skeletal material, often with extensive accompanying life-history data, is a unique and valuable source of data for both academic and conservation-based research.

SUMMARYCross-species infection among humans, chimpanzees (Pan troglodytes) and baboons (Papio spp.) is potentially a significant public health issue in Africa, and of concern in the conservation of P. troglodytes. However, to date, no statistical comparisons have been made between the prevalence, richness and composition of parasite communities in sympatric populations of baboons and P. troglodytes. We compared parasite communities in sympatric P. troglodytes and Papio papio living in a wilderness site, in the Republic of Senegal, West Africa. We asked whether, in the absence of humans, there are significant differences between these hosts in their interactions with gastrointestinal parasites. We tested whether host, location, or time of collection accounted for variation in prevalence, richness and community composition, and compared prevalence across six studies. We concluded that, despite being closely related, there are significant differences between these two hosts with respect to their parasite communities. At our study site, prevalence of Balantidium, Trichuris and Watsonius was higher in P. papio. Papio papio harboured more parasites per host, and we found evidence of a positive association between Trichuris and Balantidium in P. troglodytes but not P. papio.

Snakes are presumed to be hazards to primates, including humans, by the snake detection hypothesis (Isbell in J Hum Evol 51:1-35, 2006; Isbell, The fruit, the tree, and the serpent. Why we see so well, 2009). Quantitative, systematic data to test this idea are lacking for the behavioural ecology of living great apes and human foragers. An alternative proxy is snakes encountered by primatologists seeking, tracking, and observing wild chimpanzees. We present 4 years of such data from Mt. Assirik, Senegal. We encountered 14 species of snakes a total of 142 times. Almost two-thirds of encounters were with venomous snakes. Encounters occurred most often in forest and least often in grassland, and more often in the dry season. The hypothesis seems to be supported, if frequency of encounter reflects selective risk of morbidity or mortality.

Department of Anthropology, Oregon State University, Corvallis, OR 97331KEY WORDS Pan troglodytes; thumb; precision grip; manipulative behaviorABSTRACT It has long been assumed that stone toolmaking was a major factor in the evolution of derivedhominin hand morphology. However, stresses on thehand associated with food retrieval and processing alsohave been recognized as relevant early hominin behav-iors that should be investigated. To this end, chimpanzeefood manipulation was videotaped in the Mahale Moun-tains National Park, Tanzania. Grips and hand move-ments by 39 chimpanzees were analyzed for arborealand terrestrial feeding involving 10 food-types and asso-ciated vegetation. It was predicted that (1) new gripswould be found that had not been observed in captivity,(2) forceful precision grips would be absent from the rep-ertoire, as in captivity, and (3) precision handling wouldbe observed. New grips involving the full thumb andbuttressed index finger, and a new integrated pattern ofgrips and forceful hand movements were discovered,associated with feeding on large fruits and meat. Partici-pation of the full thumb in these grips, rather than thedistal thumb and fingers, throws light on feeding behav-iors that may have become increasingly significant fac-tors in the evolution of derived hominin thumbmorphology. The proximal thumb stabilizes food withthe flexed index finger against the pull of the teeth andprovides leverage in breaking food into portions. Isolatedqualitative observations of possibly forceful pinch by thethumb and side of the index finger highlight the needfor comparative quantitative data to test whetherhumans are unique in forceful precision gripping capa-bility. Precision handling was not seen. Am J PhysAnthropol 000:000–000, 2014.

Chimpanzees are renowned for their use of foraging tools in harvesting social insects and some populations use tools to prey on aggressive army ants (Dorylus spp.). Tool use in army ant predation varies across chimpanzee study sites with differences in tool length, harvesting technique, and army ant species targeted. However, surprisingly little is known about the detailed ecology of army ant predation. We studied army ant predation by chimpanzees (Pan troglodytes verus) at the Seringbara study site in the Nimba Mountains, Guinea (West Africa), over 10 years (2003-2013). We investigated chimpanzee selectivity with regards to army ant prey species. We assessed the temporal variation in army ant-feeding and examined whether army ant predation was related to rainfall or ripe fruit availability. Moreover, we examined whether chimpanzees showed selectivity regarding plant species used for tool manufacture, as well as the relationship between tool species preference and tool collection distance. Lastly, we measured tool properties and investigated the use of tool sets and composite tools in army ant predation. Seringbara chimpanzees preyed on one army ant species (D. nigricans) more often than expected based on encounter rates, which may be explained by the overlap in altitudinal distribution between chimpanzees and D. nigricans. Army ant predation was not related to rainfall or fruit availability. Chimpanzees were selective in their choice of tool materials and collected their preferred tool species (Alchornea hirtella) from greater distances than they did other species. Lastly, Seringbara chimpanzees used both tool sets and composite tools (tree perch) in army ant predation. Tool types (dig vs. dip) differed in width and strength, but not length. Tool composites were found at 40% of ant-feeding sites. Our study sheds new light on the ecology of army ant predation and provides novel insights into chimpanzee selection of army ant prey and tool species.

Non-human primates using stones in nature provide a rare opportunity to compare directly the behaviour of use with the resulting lithic artifacts. Wild Japanese macaques (Macaca fuscata) customarily do “stone handling” (SH = spontaneous, solitary, non-instrumental and seemingly playful manipulation of stones). Ten populations of monkeys show at least 48 behavioral variants, 13 of which entail repeated stone-on-stone or stone-on-substrate contact that is likely to yield recognizable wear patterns. We collected 10 assemblages of stones after seeing them being used, as well as “control” stones from a nearby hillside. In the first experiment, human subjects of varying degrees of knowledge of SH were asked to separate handled versus non-handled stones. Overall they were unable to do so, but the best-informed subjects were more accurate than the totally naive ones. In the second experiment, another set of totally naive subjects was tutored on key points derived from the first experiment. They scored sig...

The role of invertebrates in the evolution of human diet has been under-studied by comparison with vertebrates and plants. This persists despite substantial knowledge of the importance of the 'other faunivory', especially insect-eating, in the daily lives of non-human primates and traditional human societies, especially hunters and gatherers. Most primates concentrate on two phyla, Mollusca and Arthropoda, but of the latter's classes, insects (especially five orders: Coleoptera, Hymenoptera, Isoptera, Lepidoptera, Orthoptera) are paramount. An insect product, bees' honey, is particularly important, and its collection shows a reversal of the usual sexual division of labor. Human entomophagy involves advanced technology (fire, containers) and sometimes domestication. Insectivory provides comparable calorific and nutritional benefits to carnivory, but with different costs. Much insectivory in hominoids entails elementary technology used in extractive foraging, such as termite fishing by chimpanzees. Elucidating insectivory in the fossil and paleontological record is challenging, but at least nine avenues are available: remains, lithics, residues, DNA, coprolites, dental microwear, stable isotopes, osteology, and depictions. All are in play, but some have been more successful so far than others.

Macroscopic inspection of feces has been used to investigate primate diet. The limitations of this method to identify food-items to species level have long been recognized, but ascertaining aspects of diet (e.g., folivory) are achievable by quantifying food-items in feces. Quantification methods applied include rating food-items using a scale of abundance, estimating their percentage volume, and weighing food-items. However, verification as to whether or not composition data differ, depending on which quantification method is used during macroscopic inspection, has not been done. We analyzed feces collected from ten adult chimpanzees (Pan troglodytes schweinfurthii) of the Kanyawara community in Kibale National Park, Uganda. We compare dietary composition totals obtained from using different quantification methods and ascertain if sieve mesh size influences totals calculated. Finally, this study validates findings from direct observation of feeding by the same individuals from whom the fecal samples had been collected. Contrasting diet composition totals obtained by using different quantification methods and sieve mesh sizes can influence folivory and frugivory estimates. However, our findings were based on the assumption that fibrous matter contained pith and leaf fragments only, which remains to be verified. We advocate macroscopic inspection of feces can be a valuable tool to provide a generalized overview of dietary composition for primate populations. As most populations remain unhabituated, scrutinizing and validating indirect measures are important if they are to be applied to further understand inter- and intra-species dietary variation. Am. J. Primatol. 76:539–550, 2014. © 2014 Wiley Periodicals, Inc.

INTRODUCTION Fission-fusion is the species-typical and universal social organisation of Pan troglodytes, as recognised 45 years ago by the pioneering field research of such researchers as Goodall (1968), Nishida (1968) and Sugiyama (1968). In fission-fusion, the group (or community), sub-divides into temporary parties, which may further fragment or reunite, such that over the course of a day, an individual may be solitary or sociable to varying degrees (Aureli et al. 2008). The standard variable for measuring fission-fusion is party size, that is, the number of individuals in spatial association in any one period or point in time. Explanations for variation in party size are many, but the most prevalent one is feeding competition, so that the larger the party, the greater the competition. Thus, individuals seeking to reduce or avoid competition will fission, either to forage alone or with fewer companions. Following this line of argument, we hypothesise that party sizes will be lower during bouts of feeding than before or after feeding.

Ascertaining the full range of dietary constituents of a primate population allows the identification of habitats with important food resources and can assist efforts to conserve primates. For unhabituated populations, we can acquire otherwise unobtainable dietary information from macroscopic inspection of fecal samples. This method has made a significant contribution to understanding food intake in various primate species. Increasing knowledge of the omnivorous diet of our closest living relatives, the common chimpanzee (Pan troglodytes) and the bonobo (P. paniscus), which range and forage in various habitats to meet daily nutrient requirements, provides more scope to assess human omnivory and its evolution from our last common ancestor. However, macroscopic inspection may lead to bias toward undigested and therefore identifiable food items, e.g., fruit seeds, vs. pulverized components, e.g., leaves, that are unidentifiable at this level. This study seeks to validate findings from macroscopic inspection by comparing species identified in fecal samples from select individuals vs. data from direct observations of their feeding. We collected data from 10 adult chimpanzees of the Kanyawara community in Kibale National Park. We identified 86% of species from which fruit had been eaten vs. only 21% from which leaves had been eaten in fecal samples analyzed. This study provides empirical support for previous assumptions and confirms the limitations of macroscopic inspection of feces for identifying the nonfrugivorous dietary elements to species level. However, valuable insights into seasonality of diet can be gleaned from macroscopic inspection. Also, if we combine data on species identified in feces with direct observation of food intake, we can establish when food items were eaten, which enables estimations of gut passage rates for wild populations. Finally, analyzing fecal samples collected from various group members can provide insight into the dietary repertoire at the individual level.