Primate Research Institute, Kyoto University, Kanrin 41, Inuyama, Aichi, 484-8506, Japan.
Wildlife Research Center, Kyoto University, Kyoto, Japan.
Sci Rep. 2021 Mar 18;11(1):4967. doi: 10.1038/s41598-021-83667-2.
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 two cases of a wild bonobo adopting an infant from a different social group, the first report of cross-group adoption in great apes. In one case, the adoptive mother was already a mother of two dependent offspring. In the other case, the adoptive mother was an old parous female whose own offspring had already emigrated into a different social group. The adoptive mothers provided various maternal care to the adoptees, such as carrying, grooming, nursing, and sharing food. No aggression was observed by group members towards the out-group adoptees. In both cases, adoptees had no maternal kin-relationship with their adoptive mothers. Both adoptive mothers already had experience of rearing their own offspring. Instead, these cases of adoption may have been driven by other evolutionary adaptive traits of bonobos, such as their strong attraction to infants and high tolerance towards immatures and out-group individuals.
收养，即收养他人的后代并将其视为自己的孩子，虽然罕见，但在各种哺乳动物中广泛存在，并且可能会增加被收养者的存活率。收养也可能使养母受益，例如，她们可能会照顾近亲以获得间接适应度或学习照顾行为。在这里，我们报告了两起野生倭黑猩猩收养来自不同社会群体的婴儿的案例，这是大猿中首例跨群体收养的报告。在一个案例中，养母已经是两个依赖子女的母亲。在另一个案例中，养母是一个已经生育过的老年多产雌性，她自己的后代已经移民到了另一个社会群体。养母们为被收养者提供了各种母性照顾，如携带、梳理、哺乳和分享食物。群体成员对来自其他群体的被收养者没有表现出攻击性。在这两种情况下，被收养者与他们的养母没有母系亲属关系。这两个养母都已经有了抚养自己孩子的经验。相反，这些收养案例可能是由倭黑猩猩的其他进化适应性特征驱动的，例如它们对婴儿的强烈吸引力以及对不成熟个体和外来个体的高度容忍度。
