A Social Affordance Framework for Understanding Approach Decisions in Wild Crested Macaques ( Macaca nigra )
Abstract
Approaching conspecifics is a fundamental component of social interactions. Such decisions are typically investigated through the study of social relationships (e.g., kinship, dominance, affiliation) and their impact. In the framework, the role of social affordances, i.e., interaction opportunities arising from the immediate social environment, remains poorly understood. We investigated how context-dependent factors shape approach decisions in wild crested macaques (Macaca nigra) in North Sulawesi, Indonesia. From September 2024 to May 2025, we collected data on 27 adults (20 females, 7 males) using focal observations and an approach-specific protocol recording neighbours’ identities and behaviours at the initiation of close-proximity approaches (1 body length). We first compared data collected during approaches with focal data, then conducted within-approach analyses contrasting approached partners and bystanders. We further tested the effects of behavioural state, subgroup size and composition, including infant presence. Bayesian models revealed that affiliative, neutral, and grooming behaviours were more frequent in approach contexts than in general observations. Within approaches, individuals avoided congeners already engaged in grooming and approached individuals in neutral or affiliative states (e.g., lip-smacking, embracing). Macaques globally approached more isolated individuals or dyads. When multiple subgroups were present (i.e., multiple choices), the likelihood of being approached increased with subgroup size and was higher in subgroups containing infants. These findings indicate that macaques use behavioural cues and local social density as affordance signals, adjusting approach decisions to maximize interaction opportunities and navigate complex social environments.
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BibTeX
@misc{provin2026social,
title = {{A Social Affordance Framework for Understanding Approach Decisions in Wild Crested Macaques ( Macaca nigra )}},
author = {Adam Provin and Fannie Beurrier and Muhamad Julfikram Bawimbang and Dyah Perwitasari-Farajallah and Sébastien Ballesta and Cécile Garcia and Julie Duboscq},
howpublished = {HAL},
year = {2026},
month = jun,
doi = {10.64898/2026.06.25.734458},
url = {https://hal.science/hal-05854137v1},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - A Social Affordance Framework for Understanding Approach Decisions in Wild Crested Macaques ( Macaca nigra )
AU - Adam Provin
AU - Fannie Beurrier
AU - Muhamad Julfikram Bawimbang
AU - Dyah Perwitasari-Farajallah
AU - Sébastien Ballesta
AU - Cécile Garcia
AU - Julie Duboscq
PY - 2026
DA - 2026/06/30
PB - HAL
DO - 10.64898/2026.06.25.734458
UR - https://hal.science/hal-05854137v1
AB - Approaching conspecifics is a fundamental component of social interactions. Such decisions are typically investigated through the study of social relationships (e.g., kinship, dominance, affiliation) and their impact. In the framework, the role of social affordances, i.e., interaction opportunities arising from the immediate social environment, remains poorly understood. We investigated how context-dependent factors shape approach decisions in wild crested macaques (Macaca nigra) in North Sulawesi, Indonesia. From September 2024 to May 2025, we collected data on 27 adults (20 females, 7 males) using focal observations and an approach-specific protocol recording neighbours’ identities and behaviours at the initiation of close-proximity approaches (1 body length). We first compared data collected during approaches with focal data, then conducted within-approach analyses contrasting approached partners and bystanders. We further tested the effects of behavioural state, subgroup size and composition, including infant presence. Bayesian models revealed that affiliative, neutral, and grooming behaviours were more frequent in approach contexts than in general observations. Within approaches, individuals avoided congeners already engaged in grooming and approached individuals in neutral or affiliative states (e.g., lip-smacking, embracing). Macaques globally approached more isolated individuals or dyads. When multiple subgroups were present (i.e., multiple choices), the likelihood of being approached increased with subgroup size and was higher in subgroups containing infants. These findings indicate that macaques use behavioural cues and local social density as affordance signals, adjusting approach decisions to maximize interaction opportunities and navigate complex social environments.
ER -