Nahoko Tokuyama

• PhD
• Professor (Assistant) at Kyoto University

Objectives: Although conflicts between groups over valuable resources are common in the animal kingdom, an individual's strategy toward out-group individuals may differ according to the benefits and costs received from inter-group interactions. Groups of bonobos encounter each other frequently and may mingle and range together from a few hours to...

Patterns of coalitionary aggression among female animals are generally explained by kin selection theory. Frequent female coalitions are almost exclusively observed in female-philopatric species, where females stay in their natal group, and females typically form coalitions with their kin. Bonobos, Pan paniscus, in contrast, are male-philopatric, w...

Group-living animals need to coordinate their activity in order to maintain gregariousness. Although individuals have their own nutritional, social, and reproductive needs, they have to reach consensus to decide where and when to travel. Collective movements are the outcome of one individual’s departure, who is then followed by other group members....

Maternal cannibalism, whereby a mother consumes her own offspring, occurs in various animal taxa and is commonly explained by nutritional stress or environmental pressures. It is rare in nonhuman primates and is considered an aberrant behavior only observed under high-stress conditions. It was therefore surprising when, in the first reported case o...

This is the first report to demonstrate that a large mixed-sex party of bonobos travelled a long distance to return to the location of a snare apparently to search for a member that had been caught in it. An adult male was caught in a metallic snare in a swamp forest at Wamba, Luo Scientific Reserve, Democratic Republic of the Congo. After he escap...

Hunting and meat-eating by chimpanzees have long been attracting researchers’ attention. Although chimpanzees consume various vertebrate species, the frequency of meat-eating and prey species differ among populations and groups. Here, we present the first documented case of chimpanzees consuming Lord Derby's anomalure in the Kalinzu forest, Uganda....

When two or more animals use limited amounts of resources, such as food, mates, or shelter, competition may occur. Individuals may gain access to the same resources when the resources can be shared, or some individuals may retreat and find other resources to avoid direct conflict. However, when one or more individuals take forceful action to monopo...

Primate societies are diverse in terms of social organization and structure (Smuts et al. 1987; Boesch et al. 2002). The society, or social unit, is the set of conspecific animals that interact regularly and more commonly with each other than with members of other societies (Kappeler and van Schaik 2002). Traditionally, social organization, which h...

Bonobos (Pan paniscus) are characterized by the formation of male-philopatric groups, wherein nulliparous females typically transfer from their natal group to another. This chapter presents long-term demographic data, collected through simultaneous observations of multiple bonobo groups at Wamba, in order to investigate the timings and locations of...

Natal dispersal is a milestone in an animal's life history, but its timing in developmental trajectories may differ between species. Although the two Pan species exhibit a similar pattern of female-biased dispersal, female bonobos (P. paniscus) leave their natal groups at an earlier age than female chimpanzees (P. troglodytes). As a preliminary ste...

One of the current threats to the bonobo (Pan paniscus), a highly endangered ape species only found in the Democratic Republic of the Congo, are anthropozoonoses caused by human respiratory viruses. To date, epidemiological information regarding respiratory viral infections in bonobos is limited. In this study, we examined fecal immunoglobulin A an...

Adoption, the act of taking another individual’s offspring and treating it as one’s own, is rare but widely observed in various mammal species and may increase the survival of adoptees. Adoption may also benefit adoptive mothers, for example they might care for close kin to gain indirect fitness or to learn caregiving behaviours. Here, we report tw...

Infectious diseases constitute one of the major threats to African great apes. Bonobos (Pan paniscus) may be particularly vulnerable to the transmission of infectious diseases because of their cohesive grouping and frequent social and sexual interactions between groups. Here we report two cases of a flu-like illness and possible transmission of the...

Patterns of kinship among individuals in different groups have been rarely examined in animals. Two closest living relatives of humans, bonobos and chimpanzees share many characteristics of social systems including male philopatry, whereas one major difference between the two species is the nature of intergroup relationship. Intergroup relationship...

In many group-living mammals, mothers may increase the reproductive success of their daughters even after they are nutritionally independent and fully grown [1]. However, whether such maternal effects exist for adult sons is largely unknown. Here we show that males have higher paternity success when their mother is living in the group at the time o...

Intergroup interactions in primates vary from nonagonistic to severely aggressive. Food resources and fertile females cause intergroup aggression when groups defend resources and mates from other groups. Peaceful intermingling during intergroup encounters is rare but has been reported in several primates, including bonobos (Pan paniscus). Although...

Although both bonobos and chimpanzees are male-philopatric species, outcomes of male–male reproductive competition seem to be more closely associated with mating success in chimpanzees. This suggests that the extent of male reproductive skew is lower in bonobos. In addition, between-group male–male reproductive competition is more lethal in chimpan...

We report here where the most recent common ancestor (MRCA) of bonobos (Pan paniscus) ranged and how they dispersed throughout their current habitat. Mitochondrial DNA (mtDNA) molecular dating to analyze the time to MRCA (TMRCA) and the major mtDNA haplogroups of wild bonobos were performed using new estimations of divergence time of bonobos from o...

The scale of the y-axis of Fig. 1 is incorrect. It should be 0, 0.02, 0.04… instead of 0, 0.2, 0.4… The correct figure is given below.

Lymphocryptovirus (LCV) is one of the major gena in the herpesvirus family and is widely disseminated among primates. LCVs of human and rhesus macaques are shown to be causative agents of a number of malignant diseases including lymphoma and carcinoma. Bonobos (Pan paniscus) are highly endangered and the least studied species of the great apes. Con...

Kidnapping, one form of allomothering behaviors in which an infant is carried by a non-mother individual for a prolonged time without returning to its mother, has been observed in various primate species (Maestripieri 1994). In bonobos, it occurs rarely and all reported kidnappers were females (Neugebauer 1980; Hohmann & Fruth 2003; Vervaecke et al...

Traditional plants used for medicinal purposes by local communities around the Northern sector of Kibale National Park, Uganda. J Ethnopharmacol 136:236–245. Namukobe J, Kiremire BT, Byamukama R, Kasenene JM, Akala HM, Kamau E, Dumontet V 2014. Antiplasmodial compounds from the stem bark of Neoboutonia macroca-lyx pax. J Ethnopharmacol 162:317–322....

This paper first reviews data collected from 1976 to 2013 regarding the life histories of members of the main E1 study group of bonobos (Pan paniscus) in Wamba. The E1 group exhibited strong tendencies toward female dispersal and male residence during the entire study period, thereby exemplifying the typical characteristics of a male-philopatric an...

One of the most conspicuous behavioural differences among great apes is the paucity of tool use among wild bonobos (Pan paniscus) in comparison to chimpanzees (Pan troglodytes) who are one of the most prolific and skilled tool users in the animal kingdom. This is in spite of the fact that bonobo tool use repertories are as large and diverse as chim...

In many social species, the victim often attacks an uninvolved third individual soon after a conflict. This behaviour is called ‘redirected aggression’ or ‘redirection’, and its role(s) remain(s) controversial. We observed semi-provisioned free-ranging Japanese macaques at Iwatayama Monkey Park in Arashiyama, Kyoto, Japan, to test three hypotheses...

Bonobos (Pan paniscus) inhabit regions south of the Congo River including all areas between its southerly tributaries. To investigate the genetic diversity and evolutionary relationship among bonobo populations, we sequenced mitochondrial DNA from 376 fecal samples collected in seven study populations located within the eastern and western limits o...

Summary of DNA experiments. (TIF)

Comparison of six clades of haplotypes with mean number of pairwise haplotype differences. Mean number of pairwise haplotype differences was compared within and between clades shown in Figure 2. Values of the diagonal indicate average number of pairwise differences within clades. Those above the diagonal are average number of pairwise differences b...

Comparison of population distances with results of test for their statistical significance. Values below the diagonal indicate estimates of population pairwise FST calculated assuming Tamura-Nei mutation model. Values above the diagonal indicate P values of permutaion test (n = 1,023) for the null hypothesis of FST = 0 by the software Arlequin vers...