Mothers are the most fundamental individuals for the survival and development of their immature offspring. Sex-biased dispersal has an effect on strong and long-lasting social bonding between mothers and their philopatric offspring. Nepotistic relationships are often seen in species with male-biased dispersal but less frequently in species with female-biased dispersal. Bonobos are unique among female-biased dispersal primates in that the females are codominant with males, exert influence on the mating opportunities of their mature sons, and tolerate each other regardless of relatedness. Few studies on bonobos have examined sex differences in social relationships between juveniles and their mothers, and how this relates to mother–son and female–female cooperative relationships amongst adults. We investigated whether the association index of juveniles with their mothers changed with age depending on the sex of the juveniles in parties of bonobos at Wamba, the Democratic Republic of the Congo. We found that female bonobos had decreased party associations with their mothers prior to their emigration from the natal group, while male bonobos maintained relatively high party associations with their mothers. These results indicate that sex differences that emerge during the juvenile period in bonobos in their spatial relationships with their mothers differ from previous findings on chimpanzees, spider monkeys, and muriquis, in which philopatric sons tend to spend less time in proximity to their mothers and disperse earlier than, or at a similar age to, daughters. The contrasts between bonobos and other primate species suggest that the high social status of female bonobos relative to that of males may facilitate the extension of maternal support for their philopatric sons, and that high tolerance among unrelated females may enable the spatial independence of daughters from their mothers at an earlier stage.

中文翻译：

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在 Wamba 与母亲的政党协会中，幼年倭黑猩猩的年龄和性别差异

母亲是其未成熟后代生存和发展的最基本个体。性别偏向的传播对母亲和他们的亲子后代之间牢固而持久的社会纽带有影响。裙带关系经常出现在具有雄性偏向性扩散的物种中，但在具有雌性偏向性扩散的物种中较少见。倭黑猩猩在偏向雌性的散播灵长类动物中是独一无二的，因为雌性与雄性共存，对成熟儿子的交配机会施加影响，并且无论亲缘关系如何，都相互容忍。很少有关于倭黑猩猩的研究调查了青少年与其母亲之间社会关系的性别差异，以及这与成人之间的母子和雌性合作关系的关系。我们调查了在刚果民主共和国万巴的倭黑猩猩群体中，青少年与其母亲的关联指数是否随年龄而变化，这取决于倭黑猩猩的性别。我们发现，雌倭黑猩猩在离开出生组之前与母亲的政党联系减少了，而雄性倭黑猩猩与母亲的政党联系相对较高。这些结果表明，倭黑猩猩在幼年时期与母亲的空间关系中出现的性别差异与之前对黑猩猩、蜘蛛猴和穆里奇的发现不同，在这些发现中，有亲情的儿子与母亲的亲近时间较少，并会分散在外的空间中。 ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?早于或与女儿年龄相仿。