International Journal of Primatology

, Volume 33, Issue 5, pp 1069–1080 | Cite as

The Socioecology of Network Scaling Ratios in the Multilevel Society of Hamadryas Baboons (Papio hamadryas hamadryas)



Multilevel or modular societies characterize a range of mammalian taxa, allowing social groups to fission and fuse in response to ecological factors. The modular society of hamadryas baboons has previously been shown to consist of 4 levels: troop, band, clan, and one-male unit (OMU). A recent study by Hill et al. (Biology Letters 4:748–751, 2008) revealed a mean scaling ratio across successive levels of multilevel societies of ca. 3; this was consistent across elephants, orca, geladas, and hamadryas baboons. Here we reanalyze the scaling ratio for hamadryas baboons with previously unavailable data from Filoha. Our analysis revealed a mean scaling ratio for hamadryas of 3.28 without data on the hamadryas clan layer of organization at Filoha, but a ratio of 6.17 with these data included. This discrepancy is due to the large clan and band sizes at Filoha yielding a larger than average gap between the OMU and the clan. Further analysis revealed subsets of OMUs within clans, suggesting a 5th level of society in this population. When this 5th layer of social structure is included in the analysis, the scaling ratio at Filoha is consistent with that of other hamadryas populations and other taxa. These results suggest that a consistent mammalian scaling ratio can be used to detect previously hidden levels of organization within societies and to predict their sizes in taxa for which detailed behavioral data are not available.


Clans Hamadryas baboons Hierarchical society Multilevel social organization Scaling ratio 



We thank the Ethiopian Wildlife Conservation Authority for permission to conduct research at Filoha. The City University of New York PSC-CUNY Research Award Program (award no. 66588-0035 to L. Swedell), the New York Consortium in Evolutionary Primatology, and the City University of New York Ph.D. Program in Anthropology provided funding. For support and assistance in the field, we thank Getenet Hailemeskel, Demekech Woldearegay, Teklu Tesfaye, Getu Mamush, Denberu Tesfaye, Getu Kifle, Julian Saunders, Christine Tuaillon, and Matt Klein. We thank Cyril Grueter and 3 anonymous reviewers for comments that have greatly improved this manuscript.


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Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  1. 1.Department of Evolutionary AnthropologyDuke UniversityDurhamUSA
  2. 2.Department of Anthropology, Queens CollegeCity University of New YorkFlushingUSA

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