Toward a comparative socioecology of the genus Macaca: Different dominance styles in rhesus and stumptail monkeys

Abstract

Captive studies can make a unique contribution to primate socioecology by documenting species-typical social dispositions under controlled conditions. Recent theories seek to connect the dominance relationships, group cohesiveness, and feeding ecology of primates. The present study explores the first two aspects by comparing the social organization of rhesus (Macaca rnulatta) and stumptail monkeys ( M . arctoides). Data were collected over a period of eight years, with five different methods, on three well-established captive groups in identical environments. The groups were found to share one characteristic: a clear-cut, linear formal dominance hierarchy as expressed in teeth-baring displays. The two main study groups (one of each species) differed significantly, however, with respect to nine of eleven behavioral measures. In addition to a previously reported higher frequency of reconciliation in the stumptail group, this group showed 1) more frequent but less severe aggressive behavior, 2) greater symmetry of contests, 3) greater social tolerance, 4) more nonagonistic approaches, and 5) more allogrooming. The differences can be summarized as a contrast in dominance "style," with the stumptails having a more relaxed style and placing greater emphasis on social cohesion than the rhesus monkeys. An egalitarian attitude was also reflected in approach behavior: contacts in the rhesus group were mostly initiated by dominants, whereas contacts in the stumptail group were initiated independent of rank. Comparisons with a second rhesus group, and with published reports, suggest that while some of the observed differences are probably representative of the two species, considerable intraspecific variation does exist, and a more comprehensive program of comparative studies is needed.

A comparative network analysis of social style in macaques

“…Dominance rank has a stronger influence on the patterning of affiliative interactions in species characterized by a steep dominance gradient than in those with a more relaxed style of dominance (Waal & Luttrell 1989;Thierry et al 2004). In general, lower-ranking individuals are seen to groom and exchange body contacts more often with higher-ranking individuals, especially with the top-ranking male (Schino 2001;Nakamichi & Shizawa 2003;Silk et al 2003).…”

“…Whereas all macaque species show the same basic patterns of social organization, they display broad interspecific variation in their social style, and any evolutionary explanation must account for the covariation of behavioural traits from one species to another resulting from linkages between traits (Waal & Luttrell 1989;Thierry et al 2004;Thierry 2007). In species with strict dominance relationships, the risk of being bitten in a conflict is relatively high and the best tactic for targets of aggression is either to submit or to flee rather than to retaliate, which impairs the occurrence of affiliative interactions between previous opponents.…”

“…Social styles can be classified as 'despotic' and 'egalitarian' (Waal & Luttrell 1989;Matsumura 1999;Hemelrijk 2000), and macaque styles have been more accurately ranked on a 4-grade scale from less to more tolerant species (Thierry et al 2000;Thierry 2007). This scale is mainly based on patterns of agonistic and affiliative interactions.…”

The evolution of female social relationships in nonhuman primates

“…The third dimension is that of tolerance . As tolerance increases the severity of aggression decreases (even if aggression is still common), threats toward dominants increase, and various cohesion-enhancing behaviors (e.g., reconciliation) increase (Thierry 1985;de Waal and Luttrell 1989). These three dimensions are interrelated: tolerant and nepotistic dominance systems are only possible in systems that are basically despotic.…”

Dominance hierarchy and social grooming in female lion- tailed macaques (Macaca silenus) in the Western Ghats, India

“…A key factor that helps understand social organization is the dominance relationships among individuals of a group of primates. de Waal and Luttrell (1989) introduced the concept of "dominance styles" that referred to the speciestypical patterns of asymmetrical outcomes in agonistic interactions. van Schaik (1989) and Sterck et al (1997) considered that resource competition among females was the source of such asymmetrical relationships.…”