Stability and Change of Social Relationship Quality in Captive Chimpanzees (Pan troglodytes)

Abstract

In social animals an individual's fitness depends partly on the quality of relationships with others. Qualitative variation in relationships has been conceptualized according to a three-dimensional structure, consisting of relationship value, compatibility, and security. However, the determinants of the components and their temporal stability are not well understood. We studied relationship quality in a newly formed group of 20 captive chimpanzees made up of several previously existing social groups. We assessed dyadic relationship quality 2 yr and again 7 yr after grouping. We confirmed the existence and stability of three relationship components and labeled them value, compatibility, and approach symmetry. Previously familiar dyads had a higher value than unfamiliar dyads, especially when they were maternally or paternally related. Compatibility was higher in dyads with only females than in dyads containing a male, but familiarity did not influence compatibility. Approach symmetry was initially higher, but later lower, in familiar than unfamiliar dyads, indicating that approach symmetry of familiar dyads decreased over time. Dyadic value and compatibility were highly stable over time, which is similar to the long relationship duration found in wild chimpanzees. In sum, relationships formed earlier in life became more valuable than those formed in later adulthood, whereas nonaggressive, compatible relationships could be formed throughout life. This suggests that for immigrating individuals, high-value relationships may be relatively difficult to establish, partly explaining why wild female chimpanzees have relatively few high-quality relationships with other females. Our study supports the multicomponent structure and durability of relationships in social species.

Durability and flexibility of chimpanzee grooming patterns during a period of dominance instability

“…Similar to recent studies from the wild (e.g., Foerster et al, ; Lehmann & Boesch, ) and captivity (e.g., Fraser et al, ; Koski et al, ) we found evidence for durability of grooming patterns between chimpanzee females. They showed consistency between adjacent periods, but females shifted partner preferences between the unstable and stable periods, which were 4 years apart.…”

“…Two earlier studies have explored the effect of rank reversals in the male hierarchy on relationships within a primate group (de Waal, ; Perry, ) but none so far have explicitly considered the impact of social uncertainty on the durability of affiliation patterns in non‐human primates, and the role of social uncertainty on the durability of human social relationships is poorly understood (Bukowski, Newcomb, & Hartup, ). Chimpanzees ( Pan troglodytes ) are a suitable species to examine the role of social uncertainty on the durability of affiliation patterns as enduring affiliation patterns have been reported between males and females (Gilby & Wrangham, ; Langergraber, Mitani, & Vigilant, ; Lehmann & Boesch, ; Koski, de Vries, van de Kraats, & Sterck, ; Mitani, ), and males are known to engage in flexible social interactions which may depend on social uncertainty (e.g., Nishida, ).…”

“…However, more recent findings reveal that females can form long‐term cooperative relationships and opportunistic female–female coalitions (Boesch & Boesch‐Achermann, ; Foerster et al, ; Langergraber et al, ; Lehmann and Boesch, , ; Newton‐Fisher, ; Wakefield, ). The potential for female chimpanzees to form strong relationships was first documented in captivity (Baker & Smuts, ; de Waal , ), and subsequent captive studies have continued to provide evidence that females can form high‐quality relationships with each other (e.g., Koski, de Vries, van de Kraats, & Sterck, ; Fraser, Schino, & Aureli, ). Only one study so far has assessed temporal durability in female grooming patterns (Lehmann & Boesch, ).…”

Social network changes during space restriction in zoo chimpanzees

“…However, previous studies have noted that sex differences are influenced by captivity. In zoo chimpanzees, both males and females establish stable, high quality relationships (de Waal 1984, 1994; Fraser et al 2008; Koski et al 2012) which may account for the lack of difference in grooming network positions in our study.…”

Effect of rearing style on the development of social behaviour in young ravens (Corvus corax)

“…Accordingly, siblings always formed significantly stronger relationships compared to unfamiliar individuals (whenever the group comprised unfamiliar individuals: A and B), and to familiar partners in the parent‐ (A) and hand‐raised (C) groups. However, kin are not always the preferential partners (e.g., Lukas, Reynolds, Boesch, & Vigilant, ; Wittemyer et al, ) and beside relatedness, familiarity often plays a major role on grouping patterns and social preferences (e.g., Griffiths, Brockmark, Höjesjö, & Johnsson, ; Koski, Vries, Kraats, & Sterck, ). Depending on the nature of past interactions, familiarity can increase partners’ propensity to reciprocate interactions (Brosnan & de Waal, ), acting as a feedback loop securing valuable relationships (in primates: Seyfarth & Cheney, ; Barrett, Henzi, Weingrill, Lycett, & Hill, ; Tiddi, Aureli, Polizzi Di Sorrentino, Janson, & Schino, ; in birds: Krams, Krama, & Igaune, ; Wheatcroft & Price, ).…”