In bonobos, most cooperation in agonistic contexts occurs among females 25, most of whom outrank all adult males in the group and hardly receive coercive aggression by males 26. However, bonobos and chimpanzees differ in some fundamental social aspects such as the frequency and form of female and male cooperation, intersexual dominance relationships, and the intensity of male-male competition reviewed in 24. ![]() They share many social and physical traits, such as multi-male multi-female communities with male philopatry and typical female dispersal, a moderate sexual dimorphism with females being smaller than males and females exhibiting sexual swellings indicative of the likelihood of ovulation 19, 20, 21, 22, 23. Species with a high degree of fission-fusion dynamics offer the opportunity to assess individual partner preference through spatial associations.Īmong the species with a high degree of fission-fusion dynamics are bonobos ( Pan paniscus) and chimpanzees ( Pan troglodytes) 17, 18, which often serve as a referential model for our own evolutionary processes. In such species, individuals often range in subgroups varying in size, composition, and duration (also called parties), allowing members of a group to adapt to environmental changes including the availability of resources while concurrently maintaining a certain degree of association 15, 16. While most social species live in stable cohesive social groups, some species exhibit a high degree of fission-fusion dynamics in their grouping patterns 14. Variation in association patterns within groups has therefore been used to make inferences about several aspects of social life including reproductive strategies and potential cooperation between individuals 12, 13. Within a group, the spatial association between individuals often mirrors the pattern and strength of social relationships 6 and strong social relationships and frequent spatial association promote within-group cooperation 7, 8, 9, 10, 11. Yet animals can also derive benefits from living in a group in the form of lower predation risk, more intense territory and resource defense against other groups as well as facilitated access to mating partners 2, 4, 5. Costs of sociality include increased feeding and mating competition and the risk of disease and parasite transmission 1, 2, 3. Group-living entails costs and benefits to each individual. This indicates the need to look beyond ecology when explaining species differences in female sociality as it refutes the idea that the higher gregariousness among bonobo females is driven by ecological factors alone and highlights that the temporal distribution of female sexual receptivity is an important factor to consider when studying mammalian sociality. We find that the more frequent presence of maximally tumescent females in bonobos is associated with a significantly stronger increase in the number of female party members, independent of variation in a behavioural proxy for food abundance. ![]() While bonobo females exhibited a slightly higher average number of females in their parties, there is neither a species difference in the time females spent alone, nor in the number of female party members in the absence of sexually attractive females. While testing for proposed differences in female-female associations underlying female coalition formation in the species of the genus Pan, we find only limited evidence for a higher female-female gregariousness in bonobos. Generally, spatial association between females often mirrors patterns and strength of social relationships and cooperation within groups. Here we show that sexual signaling affects patterns of female spatial association differently in chimpanzees and bonobos, indicating its relevance in shaping the respective social systems.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |