Mielke Alexander, Samuni Liran, Preis Anna, Gogarten Jan F, Crockford Catherine, Wittig Roman M
Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire.
R Soc Open Sci. 2017 Nov 8;4(11):171296. doi: 10.1098/rsos.171296. eCollection 2017 Nov.
Grooming interactions benefit groomers, but may have negative consequences for bystanders. Grooming limits bystanders' grooming access and ensuing alliances could threaten the bystander's hierarchy rank or their previous investment in the groomers. To gain a competitive advantage, bystanders could intervene into a grooming bout to increase their own grooming access or to prevent the negative impact of others' grooming. We tested the impact of dominance rank and social relationships on grooming intervention likelihood and outcome in two sympatric primate species, Western chimpanzees () and sooty mangabeys (). In both species, rather than increasing their own access to preferred partners, bystanders intervened mainly when an alliance between groomers could have a negative impact on them: when the lower-ranking groomer was close to the bystander in rank, when either groomer was an affiliation partner whose services they could lose, or the groomers were not yet strongly affiliated with each other. Thus, bystanders in both species appear to monitor grooming interactions and intervene based on their own dominance rank and social relationships, as well as triadic awareness of the relationship between groomers. While the motivation to intervene did not differ between species, mangabeys appeared to be more constrained by dominance rank than chimpanzees.
梳理互动对梳理者有益，但可能对旁观者产生负面影响。梳理行为限制了旁观者的梳理机会，随之形成的联盟可能会威胁到旁观者的等级地位或他们之前在梳理者身上的投入。为了获得竞争优势，旁观者可能会介入梳理行为，以增加自己的梳理机会，或防止他人梳理行为带来的负面影响。我们测试了优势等级和社会关系对两种同域灵长类动物——西部黑猩猩（）和乌白眉猴（）梳理干预可能性及结果的影响。在这两个物种中，旁观者主要在梳理者之间的联盟可能对自己产生负面影响时进行干预，而不是增加自己与偏好伙伴的接触机会：当地位较低的梳理者在等级上与旁观者接近时，当任何一个梳理者是他们可能失去服务的从属伙伴时，或者当梳理者彼此之间尚未建立紧密联系时。因此，这两个物种的旁观者似乎都会监控梳理互动，并根据自己的优势等级、社会关系以及对梳理者之间关系的三元认知来进行干预。虽然干预动机在不同物种之间没有差异，但乌白眉猴似乎比黑猩猩更容易受到优势等级的限制。
