Wild primates copy higher-ranked individuals in a social transmission experiment

Abstract

Little is known about how multiple social learning strategies interact and how organisms integrate both individual and social information. Here we combine, in a wild primate, an open diffusion experiment with a modeling approach: Network-Based Diffusion Analysis using a dynamic observation network. The vervet monkeys we study were not provided with a trained model; instead they had access to eight foraging boxes that could be opened in either of two ways. We report that individuals socially learn the techniques they observe in others. After having learnt one option, individuals are 31x more likely to subsequently asocially learn the other option than individuals naïve to both options. We discover evidence of a rank transmission bias favoring learning from higher-ranked individuals, with no evidence for age, sex or kin bias. This fine-grained analysis highlights a rank transmission bias in a field experiment mimicking the diffusion of a behavioral innovation.

Processing of novel food reveal payoff and rank-biased social learning in a wild primate

“…We tested whether the diffusion followed specific social networks representing different pathways of learning such as learning from females, older individuals, related individuals or higher rankers. We discovered evidence of a transmission bias favoring learning from higher-ranked individuals, with no evidence for age, sex or kin bias (28). Present results are thus in accordance with these previous findings.…”

“…We then analyzed data from this experiment with EWA models. We predict, in accordance with another study focusing on context biases (28), that higher-ranked vervet monkeys are more influential demonstrators than others. We hypothesize that other content biases, such as frequency or payoff based (i.e.…”

“…In the present study, the two innovators were an infant and a low-ranking adult male. In another open diffusion experiment (28), the alpha male and female were the two innovators in the same two groups when tested one year before. We believe that this difference can be linked to the aforementioned experiments' methodological considerations.…”

“…Males were considered as adults once they dispersed, and females were considered as adults after they gave their first birth. Individuals that did not fulfill these criteria were considered as juveniles (28). Each group had been habituated to the presence of human observers: since 2010 for NH and since 2013 for KB.…”

Simulated poaching affects global connectivity and efficiency in social networks of African savanna elephants - an exemplar of how human disturbance impacts group-living species

“…On a day-to-day basis, they operate in matrilineal herds of adult females and their immature offspring (Wittemyer and Getz, 2007), or in transitional groups consisting of post-dispersal males of varying ages (Chiyo et al, 2011; Murphy et al, 2019). Similarly to other long-lived, widely ranging species (Brent et al, 2015; Canteloup et al, 2020), older elephants of relatively dominant social rank possess more experience than their younger conspecifics (McComb et al, 2001). For instance, compared to herds traveling with relatively subordinate matriarchs (Exposito 2008), herds led by dominant matriarchs experienced higher calf survival rates (Lee et al, 2016) and used better quality resources, frequently in protected reserves (Wittemyer et al, 2007).…”