Barbara Fruth
Max Planck Society
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Molecular Ecology | 1995
Ulrike Gerloff; Christian Schlötterer; Kornelia Rassmann; I. Rambold; Gottfried Hohmann; Barbara Fruth; Diethard Tautz
We show that nuclear DNA extracted from faeces of free living bonobos (Pan paniscus) can be used to amplify hypervariable simple sequence repeats, which can be used for paternity analysis and kinship studies. Of 130 DNA extractions of samples from 33 different animals, about two‐thirds yielded PCR products at the first attempt. For several samples only a second extraction resulted in positive amplifications. Consistency tests revealed that in some cases only one of the two alleles was amplified. Presumably this is due to a very limited amount of bonobo DNA in the sample and we suggest therefore that a sample found to be homozygous at a given locus should be typed repeatedly for verification.
Proceedings of the Royal Society of London B: Biological Sciences | 1999
Ulrike Gerloff; Bianka Hartung; Barbara Fruth; Gottfried Hohmann; Diethard Tautz
Differences in social relationships among community members are often explained by differences in genetic relationships. The current techniques of DNA analysis allow explicit testing of such a hypothesis. Here, we have analysed the genetic relationships for a community of wild bonobos (Pan paniscus) using nuclear and mitochondrial DNA markers extracted from faecal samples. Bonobos show an opportunistic and promiscuous mating behaviour, even with mates from outside the community. Nonetheless, we find that most infants were sired by resident males and that two dominant males together attained the highest paternity success. Intriguingly, the latter males are the sons of high-ranking females, suggesting an important influence of mothers on the paternity success of their sons. The molecular data support previous inferences on female dispersal and male philopatry. We find a total of five different mitochondrial haplotypes among 15 adult females, suggesting a frequent migration of females. Moreover, for most adult and subadult males in the group we find a matching mother, while this is not the case for most females, indicating that these leave the community during adolescence. Our study demonstrates that faecal samples can be a useful source for the determination of kinship in a whole community.
Nature | 2014
Micahel L. Wilson; Christophe Boesch; Barbara Fruth; Takeshi Furuichi; Ian C. Gilby; Chie Hashimoto; Catherine Hobaiter; Gottifred Hohmann; Noriko Itoh; Kathelijne Koops; Julia N. Lloyd; Tetsuro Matsuzawa; John C. Mitani; Dues C. Mjungu; David Morgan; Martin N. Muller; Roger Mundry; Michio Nakamura; Jill D. Pruetz; Anne E. Pusey; Julia Riedel; Crickette M. Sanz; Anne Marijke Schel; Nicole Simmons; Mike Waller; David P. Watts; Francis White; Roman M. Wittig; Klaus Zuberbühler; Rcihard W. Wrangham
Observations of chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) provide valuable comparative data for understanding the significance of conspecific killing. Two kinds of hypothesis have been proposed. Lethal violence is sometimes concluded to be the result of adaptive strategies, such that killers ultimately gain fitness benefits by increasing their access to resources such as food or mates. Alternatively, it could be a non-adaptive result of human impacts, such as habitat change or food provisioning. To discriminate between these hypotheses we compiled information from 18 chimpanzee communities and 4 bonobo communities studied over five decades. Our data include 152 killings (n = 58 observed, 41 inferred, and 53 suspected killings) by chimpanzees in 15 communities and one suspected killing by bonobos. We found that males were the most frequent attackers (92% of participants) and victims (73%); most killings (66%) involved intercommunity attacks; and attackers greatly outnumbered their victims (median 8:1 ratio). Variation in killing rates was unrelated to measures of human impacts. Our results are compatible with previously proposed adaptive explanations for killing by chimpanzees, whereas the human impact hypothesis is not supported.
Animal Behaviour | 2000
Gottfried Hohmann; Barbara Fruth
Female bonobos, Pan paniscus, show a mounting behaviour that differs physically from that in other primate species. They embrace each other ventroventrally and rub their genital swellings against each other. We investigated five hypotheses on the function of ventroventral mounting (genital contacts) that derive from previous studies of both primate and nonprimate species: (1) reconciliation; (2) mate attraction; (3) tension regulation; (4) expression of social status; and (5) social bonding. We collected data in six field seasons (1993-1998) from members of a habituated, unprovisioned community of wild bonobos at Lomako, Democratic Republic of Congo. No single hypothesis could account for the use of genital contacts, which appeared to be multifunctional. We found support for hypotheses 1 and 3. Rates of postconflict genital contacts exceeded preconflict rates suggesting that the display is used in the context of reconciliation. Rates of genital contacts were high when food could be monopolized and tension was high. However, genital contacts also occurred independently of agonistic encounters. Our study shows rank-related asymmetries in initiation and performance of genital contacts supporting the social status hypothesis: low-ranking females solicited genital contacts more often than high-ranking females while the latter were more often mounter than mountee. Although subordinates took more initiative to achieve genital contact, dominants mostly responded to the solicitation (ventral presentation) with mounting, indicating that the performance benefits both individuals. We suggest that genital contacts can be used to investigate both quality and dynamics of dyadic social relationships among female bonobos. Copyright 2000 The Association for the Study of Animal Behaviour.
Current Anthropology | 2003
Gottfried Hohmann; Barbara Fruth
Long-term studies on wild chimpanzees (Pan troglodytes) conducted over the past four decades have revealed extensive behavioral variation within and between local populations (McGrew 1983, Nishida et al. 1983, McGrew 1992, Boesch et al. 1994, Wrangham, de Waal, and McGrew 1994, McGrew et al. 1997, Whiten et al. 1999, McGrew et al. 2001). Because chimpanzees live in different habitats across the African continent, they have to cope with a variety of environmental conditions, and therefore the extent of behavioral variation among them is not unexpected. In response to seasonal drought, populations in West and Central Africa have developed special techniques for obtaining water (Hunt and McGrew 2002, Lanjouw 2002). Chimpanzees in dry habitats with low tree density are reported to use nests repeatedly while those living in dense forest habitats rarely use the same nest twice (Fruth and Hohmann 1996). Similarly, the frequency of combining several small trees to construct a single nest varies between populations, probably as a function of forest structure (Fruth and Hohmann 1994). Variation in the extent and quality of insectivory across populations often reflects differences in the availability of prey species (McGrew 1992). Chimpanzees at different sites use different strategies to hunt red colobus monkeys (Colobus badius), and some of this variation can be related to the behavior of the prey species, density of forest cover, and, perhaps, food competition between predator and prey (Boesch 1994, Stanford 1998).
Archive | 1996
Barbara Fruth; Gottfried Hohmann; William C. McGrew; Linda F. Marchant; Toshisada Nishida; Jane Goodall; Junichiro Itani
INTRODUCTION Over decades apes have served as either referential or conceptual models in attempts to reconstruct the path of human evolution (Ghiglieri, 1987; Wrangham, 1987). In the search for behavioral traits shared by all members of the great apes, few have turned out to be conservative, that is, common features seen in all extant hominoids, and by inference present in our common ancestor. Of these shared traits, skilled object manipulation has been of great interest in comparative analyses as a basic criterion for hominization. Tool use and tool production, however, vary tremendously not only among the four species but also within a single species. Thus the trait in common is not tool use itself, but the general ability for environmental problem solving (McGrew, 1992). Nest building is part of this ability. It is probably the most pervasive form of material skill in apes. Whether or not this trait should be considered as tool use is much disputed (Goodall, 1968; Alcock, 1972; Beck, 1980; Galdikas, 1982). Nest building is called ‘bed building’ by some investigators (Itani, 1979; Hiraiwa-Hasegawa, 1986). It is a daily habit of weaned great apes to build a place in which to rest. The technique employed depends on the site and on the available materials. Orangutans, chimpanzees and bonobos start their arboreal constructions by preparing a foundation of solid sidebranches or forks, bending, breaking and inter-weaving sidebranches crosswise.
Behaviour | 1999
Gottfried Hohmann; Ulrike Gerloff; Diethard Tautz; Barbara Fruth
Studies of captive populations of bonobos suggest that females are more gregarious than males. This seems to contradict assumed sex-differences in kinship deriving from a species-typical dispersal pattern of female exogamy and male philopatry. Here we present data on spatial associations and affiliative relations among members of one wild community (Eyengo) for which genetic relationships were identified by analysing mitochondrial and nuclear DNA. Our data from Lomako confirm the existence of spatial associations among resident females. In addition, they reveal strong social bonds between males and females. While most female-female associations did not last longer than one field season, long-term associations occurred predominantly between mixed-sex dyads and involved both close kin and unrelated individuals. Differences in social grooming appeared to be related to patterns of spatial association rather than to kinship. It is suggested that under natural conditions social organisation of bonobos is characterised by strong inter-sexual bonds. Males may benefit from bonding with females by increased reproductive success via rank acquisition. For females benefits may derive from inclusive fitness and reduced food competition. Preliminary evidence suggests that females also may benefit from protection by resident males against male intruders.
Archive | 2002
Gottfried Hohmann; Barbara Fruth
INTRODUCTION In the last 20 years, chimpanzee ( Pan troglodytes ) and bonobo ( Pan paniscus ) research has produced contrasting pictures of these two sister species. Chimpanzee society has been characterized as male dominated and structured by a linear hierarchy amongst males, with more egalitarian relations amongst females. Male dominance rank is often based on alliances with other males and exerted by intense aggression (Riss & Goodall 1977; Goodall 1986; McGrew 1996; Watts 1998). Parous females, except when they are in oestrus, tend to avoid travelling with males in order to prevent aggression and to improve their foraging efficiency (Williams et al ., Chapter 14; Wrangham, Chapter 15). Consequently, parties are relatively small and often male biased (Nishida 1979; Wrangham 1986; Wrangham et al . 1992; Boesch & Boesch-Achermann 2000). In comparison, bonobo society is characterized by egalitarian relations between the sexes (Furuichi 1997) and females may collaborate to defend food sources against males (Idani 1991; Parish 1994; Hohmann & Fruth 1996;Vervaecke et al ., 2000). Males establish dominance relationships with each other but aggression amongst males and between the sexes is less intense than in chimpanzees, and conflicts are often settled in a non-agonistic way (Furuichi & Ihobe 1994; de Waal 1995). Compared to chimpanzees, bonobo parties are large and biased towards females. Recently, the behavioural contrasts between the two Pan species have been questioned (Stanford 1998) for various reasons. These include scarcity of information from wild bonobos, and the failure to compare data from wild chimpanzees with what is known from studies of captive bonobos. The goal of this chapter is to address these issues by providing new data on the social organization of wild bonobos.
Behaviour | 2003
Gottfried Hohmann; Barbara Fruth
Previous work on bonobos (Pan paniscus) has focused on the role of aggression in the context of conflict resolution in captive groups. This study investigates events of aggressive behaviour of wild bonobos to evaluate its significance in the context of mating. Temporal association (15 minutes) between aggression and mating was used to assume functional relationship. The proportion of events that were found to be related to mating activity was highest for female-female aggression followed by male-male, male-female, and female-male aggression. The results suggest that intrasexual aggression is used to manipulate the mating success of competitors: Males competed for access to oestrus females, aggression between males was high on mating days, and aggressors had higher mating rates than targets. Harassment by females disturbed mating attempts of targets, the rate of aggression increased with the number of oestrous females per party and following harassment, aggressors tended to mate more often with the male partner of the target female. Unlike intrasexual aggression, support for the predicted functions of inter-sexual aggression in the context of mating was weak. Aggression by males against females was rare and was almost never followed by mating between aggressor and target. Female aggression against males occurred frequently but appeared to be independent of mating behaviour. The results did not support the female-defence alliance hypothesis (Parish, 1996). However, when males and females engaged in close association, the rate of aggression tended to be lower and rates of mating were higher than during control periods. We suggest that male intersexual aggression is incompatible with intersexual bonding and propose that the potential benefits that males derive from affiliative long-term association with females prevent males from being aggressive against females.
International Journal of Primatology | 1994
Gottfried Hohmann; Barbara Fruth
We report the physical structure and use of a distance call (high-hoot) by wild bonobos (Pan paniscus).Although spectrographic analyses reveal high structural variability, the total sample can be subdivided according to the composition of units—the presence or absence of an initial segment—and the range of the lowest harmonic. Analyses of samples from male—female pairs,vocalizing simultaneously and in close proximity, reveal that both animals utter calls in more or less precise temporal alternation but with different spectral ranges. Whether these differences are gender-specific or related to other factors, such as age or the social relations between particular individuals, is not clear. We suggest that (a) individuals of the same party may coordinate their vocal activity on both the temporal and the spectral level and (b) high hootings stimulate emission of equal vocalizations by members of other parties and may increase cohesion among community members. Comparison of a restricted number of spectrograms from known individuals indicates that bonobos may be able to adjust spectral parameters of one type of distance calls (high- hoot) according to corresponding calls of conspecifics.