, Volume 60, Issue 3, pp 191–202 | Cite as

Comparative social grooming networks in captive chimpanzees and bonobos

  • Michelle A. RodriguesEmail author
  • Emily R. Boeving
Special Feature: Original Article Social networks analysis in primates, a multilevel perspective


Despite similar dispersal patterns, models of Pan sociality emphasize sex differences in social bonding between the two species. Such disparities are attributed to hypothesized differences in environmental selective pressures that structure association patterns. However, recent research documents greater within-species variation in social bonds in both species. Here, we examine grooming networks in captive chimpanzees at the North Carolina Zoo, and captive bonobos at the Columbus Zoo. We hypothesized that male–female grooming relationships would be the strongest in both species, but that males and females of both species would not significantly differ between centrality, strength, or clustering. Via Mantel tests, we found that neither bonobos (t = − 0.070, r = − 0.009, two-tailed p = 0.942) nor chimpanzees (t = − 0.495, r = − 0.0939, two-tailed p = 0.6205) had significant differences in grooming between or within sexes. Neither species had significant sex differences in centrality, strength, or clustering. To account for idiosyncratic factors affecting grooming distribution, we examined the effect of origin, kinship, and group tenure on social network position. We found that wild-born bonobos exhibited greater eigenvector centrality (t = − 2.592, df = 9, p = 0.29) and strength (t = − 2.401; df = 9, p = 0.040), and group tenure was significantly correlated with strength (r = 0.608; N = 11, p − 0 = 0.47). None of these factors varied with social network position in chimpanzees. Our findings suggest that in captive settings, idiosyncratic factors related to individual history play a greater role in structuring social networks. Such variation may point to the behavioral flexibility inherent in fission–fusion networks, and mirror between-site variation found in wild chimpanzees. However, some idiosyncratic factors shaping captive networks may be an artifact of captivity.


Grooming Social networks Pan Chimpanzees Bonobos 



We appreciate the role of the staff of the Columbus Zoo and Aquarium and the North Carolina Zoo in facilitating this research and their diligent care of the bonobos and chimpanzees. Specifically, we are grateful to Audra Meinelt and the keeper staff at the Columbus Zoo, and Corinne Kendall, Richard Bergl, Jennifer Ireland, and the keeper staff at the North Carolina Zoo. Additionally, we appreciate the work that Steve Ross and the Chimpanzee Species Survival Plan put into reviewing the proposed research and facilitating high chimpanzee welfare standards. We also appreciate discussions with Jessica Walz, Anna Kordek, Dawn Kitchen, Monique Fortunato, Colin Brand, and Ashley Edes in the development of this project. This manuscript was strengthened by the helpful commentary from anonymous reviewers.


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© Japan Monkey Centre and Springer Japan KK, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Beckman Institute for Science and TechnologyUniversity of IllinoisUrbanaUSA
  2. 2.Department of PsychologyFlorida International UniversityMiamiUSA

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