Scalar social dynamics in female vervet monkey cohorts

Abstract

Primate social life and behaviour is contingent on a number of levels: phylogenetic, functional and proximate. Although this contingency is recognized by socioecological theory, variability in behaviour is still commonly viewed as ‘noise’ around a central tendency, rather than as a source of information. An alternative view is that selection has acted on social reaction norms that encompass demographic variation both between and within populations and demes. Here, using data from vervet monkeys ( Chlorocebus aethiops pygerythrus ), we illustrate how this alternative approach can provide a more nuanced account of social structure and its relation to contingent events at the ecological and demographic levels. Female vervets in our South African study population live in large groups, where they experience demographic stress and increased levels of feeding competition relative to an East African population in Amboseli, Kenya. Females in the South African population did not respond to this stress by intensifying competition for high-value grooming partners to help alleviate the effects of this stress, did not show the expected rank-related patterns of grooming, nor did they show any spatial association with their preferred grooming partners. Increased group size therefore resulted in a reorganization of female social engagement that was both qualitatively and quantitatively different to that seen elsewhere, and suggests that female vervets possess the flexibility to shift to alternative patterns of social engagement in response to contingent ecological and demographic conditions.

Variation in the social organization of gorillas: Life history and socioecological perspectives

“…47,116,118,122 This study also lends support to the concept of variability selection, in which behavioral adaptations to environmental variability may reflect more generalist than specialist strategies that may result in some degree of mismatch between ecology and behavior in the short term, but lead to long term adaptive flexibility. 123,124 Gorillas live in a wide range of ecological conditions (…”

Bonobos Show Limited Social Tolerance in a Group Setting: A Comparison with Chimpanzees and a Test of the Relational Model

“…Thus far, intraspecific variation in social tolerance has been examined only rarely [Brosnan, 2006;Melis et al, 2006;Cronin et al, 2014]. However, the flexibility of primate social dynamics is becoming increasingly apparent, with social groups of the same species showing variation in mating systems, social spacing and hierarchical structure [Sapolsky, 2006;Henzi et al, 2013;Kappeler et al, 2013;Schradin, 2013]. Previous work on captive bonobo groups also warns against generalizations from data stemming from a single captive group, as groups were found to differ in expression of dominance relationships and social bonding [Stevens et al, 2008].…”

Constraints and flexibility in mammalian social behaviour: introduction and synthesis

“…Using a long-term dataset, Blumstein [142] demonstrates that demographic dynamics impact several aspects of social organization and social structure in marmots. Henzi et al [152] use detailed comparisons of female social behaviour between two populations of vervet monkeys with different group sizes to test the possibility that selection has acted on social reaction norms that encompass demographic variation both between and within populations. Cantor & Whitehead [153] analyse patterns of group-specific social behaviour transmitted by social learning among whales and dolphins to test the proposition that culture and social structure mutually affect each other.…”