How can social network analysis improve the study of primate behavior?

Abstract

When living in a group, individuals have to make trade-offs, and compromise, in order to balance the advantages and disadvantages of group life. Strategies that enable individuals to achieve this typically affect inter-individual interactions resulting in nonrandom associations. Studying the patterns of this assortativity using social network analyses can allow us to explore how individual behavior influences what happens at the group, or population level. Understanding the consequences of these interactions at multiple scales may allow us to better understand the fitness implications for individuals. Social network analyses offer the tools to achieve this. This special issue aims to highlight the benefits of social network analysis for the study of primate behaviour, assessing it's suitability for analyzing individual social characteristics as well as group/population patterns. In this introduction to the special issue, we first introduce social network theory, then demonstrate with examples how social networks can influence individual and collective behaviors, and finally conclude with some outstanding questions for future primatological research.

A comparative network analysis of social style in macaques

“…Such species-specific patterns at the level of social interactions and relationships produce interspecific variations at the level of social structures. By providing methods to investigate sets of relationships quantitatively, social network analyses give us the possibility to recognize the overall properties of a social structure, and the place of each individual within this structure (Croft et al 2008;Whitehead 2008;Sueur et al 2011). This study demonstrates that the social styles of macaque species, or at least in those situated at the extremities of the 4-grade scale (despotic/grade 1 versus egalitarian/grade 4: Thierry et al 1994, Matsumura 1999, can be successfully compared using network analyses.…”

“…We assessed dominance relationships in each group using supplantations and unidirectional conflicts spontaneously occurring in groups plus those recorded during drinking competition tests around a single source of orange fruit juice (see Thierry et al 1994). We then ranked individuals in a matrix of interactions, and used Matman software to check for linearity in the dominance hierarchy (de Vries et al 1993;Sueur et al 2011).…”

“…Numbers indicate the hierarchical rank of each individual. Distances between individuals represent their relationships in term of numbers of body contacts, which were calculated via multidimensional scaling (Sueur et al 2011). Similar shapes characterized individuals belonging to the same matriline.…”

“…At the group level, affiliative relationships underpin various patterns of social life such as coalitions, collective movements or information transmission (Chepko- Sade & Sade 1979;Silk et al 2004;Sueur & Petit 2008;Voelkl & Noë 2008). Coalitions allow individuals to win in social competition or to gain support in collective decisions by recruiting mates and kin (Chapais 1995); moreover, some key individuals can favour the spread of information or disease by their central position in social networks (Sueur et al 2011).…”

Context-dependent hierarchies in pigeons

“…In species with highly asymmetrical dominance relationships, such as gray wolves (7), mountain gorillas (8), and chacma baboons (9), there is a consistent trend for dominants to lead. This effect may be mediated by factors other than dominance, such as the central position of dominants in the association network (10) or their greater metabolic needs as a result of body size. Decision-making is more egalitarian in species where dominance relationships are weak or absent, such as in Tonkean macaques (11).…”