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Intragroup Behavioral Changes Following Intergroup Conflict in Mountain Gorillas (Gorilla beringei beringei)

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Abstract

Group-living animals face a number of threats from extragroup conspecifics: from individuals seeking mating opportunities to rival groups attempting to access limited resources. The consequences of intergroup interactions can therefore include loss of mates, increased energy expenditure, and injury or death. There is increasing evidence that aggressive intergroup interactions can affect subsequent intragroup behavior, and that such post-conflict behavior may be directly related to the threats posed by different opponent groups (e.g., familiar vs. unfamiliar). However, empirical evidence for changes in intragroup behavior following intergroup conflict in social animals is limited. We compared the proximity and behavior of group members before and after 84 aggressive intergroup interactions involving 14 study groups of wild, habituated mountain gorillas (Gorilla beringei beringei) in Volcanoes National Park, Rwanda. Intergroup conflict affected subsequent intragroup behavior in several ways. We found that immediate movement away from the opponent following intergroup conflict was less likely between familiar groups compared to unfamiliar groups. However, both winning and losing groups spent twice as much time moving post-conflict, and losing groups spent less time resting. There was an increase in female intragroup affiliative interactions and a decrease in male intragroup agonistic interactions post-conflict. These results demonstrate that such intergroup contests can influence intragroup dynamics beyond the immediate period of interaction.

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References

  • Alexander, R. D., & Bargia, G. (1978). Group selection, altruism, and the levels of organization of life. Annual Review of Ecology and Systematics, 9, 449–474.

    Article  Google Scholar 

  • Arnott, G., & Elwood, R. W. (2009). Assessment of fighting ability in animal contests. Animal Behaviour, 77, 991–1004.

    Article  Google Scholar 

  • Arseneau-Robar, T. J. M., Taucher, A. L., Muller, E., van Schaik, C., Bshary, R., & Willems, E. P. (2016). Female monkeys use both the carrot and the stick to promote male participation in intergroup fights. Proceedings of the Royal Society of London B: Biological Sciences, 283, 20161817.

    Article  Google Scholar 

  • Batchelor, T. P., & Briffa, M. (2010). Influences on resource-holding potential during dangerous group contests between wood ants. Animal Behaviour, 80, 443–449.

    Article  Google Scholar 

  • Bowles, S. (2009). Did warfare among ancestral hunter-gatherers affect the evolution of human social behaviors? Science, 324, 1293–1298.

    Article  CAS  PubMed  Google Scholar 

  • Bradley, B. J., Doran-Sheehy, D. M., Lukas, D., Boesch, C., & Vigilant, L. (2004). Dispersed male networks in western gorillas. Current Biology, 14, 510–513.

    Article  CAS  PubMed  Google Scholar 

  • Caillaud, D., Ndagijimana, F., Giarrusso, A. J., Vecellio, V., & Stoinski, T. S. (2014). Mountain gorilla ranging patterns: Influence of group size and group dynamics. American Journal of Primatology, 76, 730–746.

    Article  PubMed  Google Scholar 

  • Cheney, D. L. (1992). Intragroup cohesion and intergroup hostility: The relation between grooming distibutions and intergroup competition among female primates. Behavioral Ecology, 3, 334–345.

    Article  Google Scholar 

  • Cheney, D. L., & Seyfarth, R. M. (1987). Influence of intergroup competition on the survival and reproduction of female vervet monkeys. Behavioral Ecology and Sociobiology, 21, 375–386.

    Article  Google Scholar 

  • Christensen, C., & Radford, A. N. (2018). Dear enemies or nasty neighbors? Causes and consequences of variation in the responses of group-living species to territorial intrusions. Behavioral Ecology. https://doi.org/10.1093/beheco/ary010.

    Article  Google Scholar 

  • Cords, M. (2002). Friendship among adult female blue monkeys (Cercopithecus mitis). Behaviour, 139, 291–314.

    Article  Google Scholar 

  • Crofoot, M. C. (2007). Mating and feeding competition in white-faced capuchins (Cebus capucinus): The importance of short- and long-term strategies. Behaviour, 144, 1473–1495.

    Article  Google Scholar 

  • Crofoot, M. C. (2013). The cost of defeat: Capuchin groups travel further, faster and later after losing conflicts with neighbors. American Journal of Physical Anthropology, 152, 79–85.

    Article  PubMed  Google Scholar 

  • Crofoot, M. C., Gilby, I. C., Wikelski, M. C., & Kays, R. W. (2008). Interaction location outweighs the competitive advantage of numerical superiority in Cebus capucinus intergroup contests. Proceedings of the National Academy of Sciences of the USA, 105, 577–581.

  • di Sorrentino, E. P., Schino, G., Massaro, L., Visalberghi, E., & Aureli, F. (2012). Between-group hostility affects within-group interactions in tufted capuchin monkeys. Animal Behaviour, 83, 445–451.

    Article  Google Scholar 

  • Dunbar, R. I. M., & Dunbar, P. (1988). Maternal time budgets of gelanda baboons. Animal Behaviour, 36, 970–980.

    Article  Google Scholar 

  • Eckardt, W., Stoinski, T. S., Rosenbaum, S., Umuhoza, M. R., & Santymire, R. (2016). Validating faecal glucocorticoid metabolite analysis in the Virunga mountain gorilla using a natural biological stressor. Conservation Physiology, 4. https://doi.org/10.1093/conphys/cow029.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  • Eckardt, W., Stoinski, T. S., Rosenbaum, S., & Santymire, R. (2019). Social and ecological fators alter stress physiology of Virunga moutnain gorillas (Gorilla beringei beringei). Ecology and Evolution. https://doi.org/10.1002/ece3.5115.

    Article  PubMed  PubMed Central  Google Scholar 

  • French, J. A., Schaffner, C. M., Shepherd, R. E., & Miller, M. E. (1995). Familiarity with intruders modulates agonism towards outgroup conspecifics in wied’s black-tufted-ear marmoset (Callithrix kuhli: primates, callitrichidae). Ethology, 99, 24–38.

    Article  Google Scholar 

  • Furrer, R. D., Kyabulima, S., Willems, E. P., Cant, M. A., & Manser, M. B. (2011). Location and group size influence decisions in simulated intergroup encounters in banded mongooses. Behavioral Ecology, 22, 493–500.

    Article  Google Scholar 

  • Ganas, J., & Robbins, M. M. (2005). Ranging behavior of the mountain gorillas (Gorilla beringei beringei) in Bwindi Impenetrable National Park, Uganda: A test of the ecological constraints model. Behavioural Ecology and Sociobiology, 58, 277–288.

    Article  Google Scholar 

  • Gray, M., Roy, J., Vigilant, L., Fawcett, K., Basabose, A., et al (2013). Genetic census reveals increased but uneven growth of a critically endangered mountain gorilla population. Biological Conservation, 158, 230–238.

    Article  Google Scholar 

  • Grueber, C. E., Nakagawa, S., Laws, R. J., & Jamieson, I. G. (2011). Multimodel inference in ecology and evolution: Challenges and solutions. Journal of Evolutionary Biology, 24, 699–711.

    Article  CAS  PubMed  Google Scholar 

  • Grueter, C. C. (2013). No effect of inter-group conflict on within-group harmony in non-human primates. Communicative and Integrative Biology, 6, e26801–e26803.

    Article  PubMed  PubMed Central  Google Scholar 

  • Grueter, C. C., Ndamiyabo, F., Plumptre, A. J., Abavandimwe, D., Mundry, R., et al (2013). Long-term temporal and spatial dynamics of food availability for endangered mountain gorillas in Volcanoes National Park, Rwanda. American Journal of Primatology, 75, 267–280.

    Article  PubMed  Google Scholar 

  • Grueter, C. C., Deschner, T., Behringer, V., Fawcett, K., & Robbins, M. M. (2014). Socioecological correlates of energy balance using urinary C-peptide measurements in wild female mountain gorillas. Physiology and Behavior, 127, 13–19.

    Article  CAS  PubMed  Google Scholar 

  • Grueter, C. C., Robbins, A. M., Abavandimwe, D., Vecellio, V., Ndagijimana, F., et al (2016). Causes, mechanisms, and consequences of contest competition among female mountain gorillas in Rwanda. Behavioral Ecology, 27, 766–776.

    Article  Google Scholar 

  • Harcourt, A. H. (1979). Social relationships between adult male and female mountain gorillas in the wild. Animal Behaviour, 27, 325–342.

    Article  Google Scholar 

  • Harcourt, A. H., Stewart, K. S., & Fossey, D. (1976). Male emigration and female transfer in mountain gorillas. Nature, 263, 226–227.

    Article  Google Scholar 

  • Harris, T. R. (2006). Between-group contest competition for food in a highly folivorous population of black and white colobus monkeys (Colobus guereza). Behavioral Ecology and Sociobiology, 61, 317–329.

    Article  Google Scholar 

  • Harris, T. R. (2007). Testing mate, resource and infant defence functions of intergroup aggression in non-human primates: Issues and methodology. Behaviour, 144, 1521–1535.

    Article  Google Scholar 

  • Heinsohn, R., & Packer, C. (1995). Complex cooperative strategies in group-territorial African lions. Science, 269, 1260–1262.

    Article  CAS  PubMed  Google Scholar 

  • Hill, J., & Gelman, A. (2007). Data analysis using regression and multilevel/hierarchical models. Cambridge: Cambridge University Press.

    Google Scholar 

  • Ibáñez, A., Marzal, A., López, P., & Martín, J. (2013). Boldness and body size of male Spanish terrapins affect their responses to chemical cues of familiar and unfamiliar males. Behavioral Ecology and Sociobiology, 67, 541–548.

    Article  Google Scholar 

  • IBM Corp. Released (2015). IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp.

  • Janson, C. H., & van Schaik, C. P. (1988). Recognizing the many faces of primate food competition: Methods. Behaviour, 105, 165–186.

    Article  Google Scholar 

  • Kitchen, D. M., & Beehner, J. C. (2007). Factors affecting individual participation in group-level aggression among non-human primates. Behaviour, 144, 1551–1581.

    Article  Google Scholar 

  • Koch, F., Signer, J., Kappeler, P. M., & Fichtel, C. (2016). Intergroup encounters in Verreaux’s sifakas (Propithecus verreauxi): Who fights and why? Behavioral Ecology and Sociobiology, 70, 797–808.

    Article  PubMed  PubMed Central  Google Scholar 

  • Langergraber, K. E., Watts, D. P., Vigilant, L., & Mitani, J. C. (2017). Group augmentation, collective action, and territorial boundary patrols by male chimpanzees. Proceedings of the National Academy of Sciences of the USA, 114, 7337–7342.

  • Lazaro-Perea, C. (2001). Intergroup interactions in wild common marmosets, Callithrix jacchus: Territorial defence and assessment of neighbours. Animal Behaviour, 62, 11–21.

    Article  Google Scholar 

  • Majolo, B., Ventura, R., & Koyama, N. F. (2005). Sex, rank and age differences in the Japanese macaque (Macaca fuscata yakui) participation in inter-group encounters. Ethology, 111, 455–468.

    Article  Google Scholar 

  • Majolo, B., de Bortoli Vizioli, A., & Lehmann, J. (2016). The effect of intergroup competition on intragroup affiliation in primates. Animal Behaviour, 114, 13–19.

    Article  Google Scholar 

  • Markham, A. C., Guttal, V., Alberts, S. C., & Altmann, J. (2013). When good neighbors don’t need fences: Temporal landscape partitioning among baboon social groups. Behavioual Ecology and Sociobiology, 67, 875–884.

    Article  Google Scholar 

  • Mirville, M. O., Ridley, A. R., Samedi, J. P. M., Vecellio, V., Ndagijimana, F., et al (2018a). Factors influencing individual participation during intergroup interactions in mountain gorillas. Animal Behaviour, 144, 75–86.

    Article  Google Scholar 

  • Mirville, M. O., Ridley, A. R., Samedi, J. P. M., Vecellio, V., Ndagijimana, F., et al (2018b). Low familiarity and similar ‘group strength’ between opponents increase the intensity of intergroup interactions in mountain gorillas (Gorilla beringei beringei). Behavioral Ecology and Sociobiology, 72. https://doi.org/10.1007/s00265-018-2592-5.

  • Monclus, R., Saavedra, I., & de Miguel, J. (2014). Context-dependent responses to neighbours and strangers in wild European rabbits (Oryctolagus cuniculus). Behavioural Processes, 106, 17–21.

    Article  PubMed  Google Scholar 

  • Nunn, C. L. (2000). Collective benefits, free-riders, and male extra-group conflict. In P. M. Kappeler (Ed.), Primate males: Causes and consequences of variation in group composition (pp. 192–204). Cambridge: Cambridge University Press.

    Google Scholar 

  • Payne, H. F. P., Lawes, M. J., & Henzi, S. P. (2003). Competition and the exchange of grooming among female samango monkeys (Cercopithecus mitis erythrarchus). Behaviour, 140, 453–471.

    Article  Google Scholar 

  • Radford, A. N. (2005). Group-specific vocal signatures and neighbour–stranger discrimination in the cooperatively breeding green woodhoopoe. Animal Behaviour, 70, 1227–1234.

    Article  Google Scholar 

  • Radford, A. N. (2008a). Duration and outcome of intergroup conflict infleunces intragroup affiliative behaviour. Proceedings of the Royal Society of London B: Biological Sciences, 275, 2787–2791.

    Article  PubMed  PubMed Central  Google Scholar 

  • Radford, A. N. (2008b). Type of threat influences postconflict allopreening in a social bird. Current Biology, 18, R114–R115.

    Article  CAS  PubMed  Google Scholar 

  • Radford, A. N. (2011). Preparing for battle? Potential intergroup conflict promotes current intragroup affiliation. Biology Letters, 7, 26–29.

    Article  PubMed  Google Scholar 

  • Radford, A., Majolo, B., & Aureli, F. (2016). Within-group behavioural consequencs of between-group conflict. Proceedings of the Royal Society of London B: Biological Sciences, 283, 20161567.

    Article  Google Scholar 

  • Richter, C., Heesen, M., Nenadic, O., Ostner, J., & Schulke, O. (2016). Males matter: Increased home range size is associated with the number of resident males after controlling for ecological factors in wild Assamese macaques. American Journal of Physical Anthropology, 159, 52–62.

    Article  PubMed  Google Scholar 

  • Robbins, M. M. (1995). A demographic analysis of male life histories and social structure of mountain gorillas. Behaviour, 132, 21–47.

    Article  Google Scholar 

  • Robbins, M. M., & Sawyer, S. C. (2007). Intergroup encounters in mountain gorillas of Bwindi Impenetrable National Park, Uganda. Behaviour, 144, 1497–1519.

    Article  Google Scholar 

  • Rosenbaum, S., Hirwa, J. P., Silk, J. B., Stoinski, T. S., & Ebensperger, L. (2016a). Relationships between adult male and maturing mountain gorillas (Gorilla beringei beringei) persist across developmental stages and social upheaval. Ethology, 122, 134–150.

    Article  Google Scholar 

  • Rosenbaum, S., Maldonado-Chaparro, A. A., & Stoinski, T. S. (2016b). Group structure predicts variation in proximity relationships between male-female and male-infant pairs of mountain gorillas (Gorilla beringei beringei). Primates, 57, 17–28.

    Article  CAS  PubMed  Google Scholar 

  • Rosenbaum, S., Vecellio, V., & Stoinski, T. (2016c). Observations of severe and lethal coalitionary attacks in wild mountain gorillas. Scientific Reports, 6, 37018.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  • Samuni, L., Mielke, A., Preis, A., Crockford, C., & Wittig, R. M. (in press). Intergroup competition enhances chimpanzee in-group cohesion. International Journal of Primatology.

  • Sapolsky, R. M., Romero, L. M., & Munck, A. U. (2000). How do glucocorticoids influence stress responses? Integrating permissive, suppressive, stimulatory, and preparative actions. Endocrine Reviews, 21, 55–89.

    CAS  PubMed  Google Scholar 

  • Scarry, C. J., & Tujague, M. P. (2012). Consequences of lethal intragroup aggression and alpha male replacement on intergroup relations and home range use in tufted capuchin monkeys (Cebus apella nigritus). American Journal of Primatology, 74, 804–810.

    Article  PubMed  Google Scholar 

  • Schaller, G. (1963). The mountain gorilla. Chicago: University of Chicago Press.

    Google Scholar 

  • Seiler, N., Boesch, C., Mundry, R., Stephens, C., & Robbins, M. M. (2017). Space partitioning in wild, non-territorial mountain gorillas: The impact of food and neighbours. Royal Society Open Science, 4, 170720.

    Article  PubMed  PubMed Central  Google Scholar 

  • Seiler, N., Boesch, C., Stephens, C., Ortmann, S., Mundry, R., & Robbins, M. M. (2018). Social and ecological correlates of space use patterns in Bwindi mountain gorillas. Americal Journal of Primatology, 80(4), e22754.

    Article  Google Scholar 

  • Sicotte, P. (1993). Inter-group encounters and female transfer in mountain gorillas: Influence of group composition on male behavior. American Journal of Primatology, 30, 21–36.

    Article  PubMed  Google Scholar 

  • Siracusa, E., Boutin, S., Humphries, M. M., Gorrell, J. C., Coltman, D. W., et al (2017). Familiarity with neighbours affects intrusion risk in territorial red squirrels. Animal Behaviour, 133, 11–20.

    Article  Google Scholar 

  • Symonds, M. R. E., & Moussalli, A. (2011). A brief guide to model selection, multimodel inference and model averaging in behavioural ecology using Akaike’s information criterion. Behavioral Ecology and Sociobiology, 65, 13–21.

    Article  Google Scholar 

  • Temeles, E. J. (1994). The role of neighbours in territorial systems: When are they ‘dear enemies’? Animal Behaviour, 47, 339–350.

    Article  Google Scholar 

  • Thompson, F. J., Marshall, H. H., Vitikainen, E. I. K., & Cant, M. A. (2017). Causes and consequences of intergroup conflict in cooperative banded mongooses. Animal Behaviour, 126, 31–40.

    Article  Google Scholar 

  • Tort, L., & Teles, M. (2011). The endocrine response to stress: A comparative view. In F. Akin (Ed.), Basic and clinical endocrinology up-to-date (pp. 263–286) InTech. http://cdn.intechweb.org/pdfs/21809.pdf

  • van Belle, S., & Scarry, C. J. (2015). Individual participation in intergroup contests is mediated by numerical assessment strategies in black howler and tufted capuchin monkeys. Philosophical Transactions of the Royal Society of London B: Biological Sciences, 370, 20150007.

    Article  PubMed  PubMed Central  Google Scholar 

  • van Schaik, C., & van Hooff, J. A. R. A. M. (1983). On the ultimate causes of primate social systems. Behaivour, 85, 91–117.

    Article  Google Scholar 

  • Watts, D. P. (1989). Infanticide in mountain gorillas: New cases and a reconsideration of the evidence. Ethology, 81, 1–18.

    Article  Google Scholar 

  • Watts, D. P. (1994a). Agonistic relationships between female mountain gorillas (Gorilla gorilla beringei). Behavioural Ecology and Sociobiology, 34, 347–358.

    Article  Google Scholar 

  • Watts, D. P. (1994b). The influence of male mating tactics on habitat use in mountain gorillas (Gorilla gorilla beringei). Primates, 35, 35–47.

    Article  Google Scholar 

  • Watts, D. P. (1998). Seasonality in the ecology and life histories of mountain gorillas (Gorilla gorilla beringei). International Journal of Primatology, 19, 929–948.

    Article  Google Scholar 

  • Wich, S. A., & Sterck, E. H. M. (2007). Familiarity and threat of opponents determine variation in Thomas langur (Presbytis thomasi) male behaviour during between-group encoutners. Behaviour, 144, 1583–1598.

    Article  Google Scholar 

  • Willems, E. P., Hellriegel, B., & van Schaik, C. P. (2013). The collective action problem in primate territory economics. Proceedings of the Royal Society of London B: Biological Sciences, 280, 20130081.

    Article  Google Scholar 

  • Wilson, E. O. (1975). Sociobiology: The new synthesis. Cambridge, MA: Harvard University Press.

    Google Scholar 

  • Wrangham, R. W. (1980). An ecological model of female-bonded primate groups. Behaviour, 75, 262–300.

    Article  Google Scholar 

  • Wright, E., & Robbins, M. M. (2014). Proximate mechanisms of contest competition among female Bwindi mountain gorillas (Gorilla beringei beringei). Behavioral Ecology and Sociobiology, 68, 1785–1797.

    Article  Google Scholar 

  • Yi, Y., Fichtel, C., Kim, E., & Choe, J. C. (in press). Impacts of inter-group interactions on intra-group behavioural changes in Javan gibbons (Hylobates moloch). International Journal of Primatology.

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Acknowledgments

We wish to thank Rwanda Development Board and Ministry of Education, Rwanda for permission to conduct research in the Volcanoes National Park. We thank DFGFI for the research collaboration and the ongoing support and are incredibly thankful to all the Karisoke trackers, field assistants, and researchers over the study period who conducted the vast majority of the demographic and behavioral data collection used in this project. Special thank you to the field coordinators over the study period—Bosco Bizumuremyi, Fidele Uwimana, Francois Xavier Ndungutze (Conseiller), and Jean Damascene Hategekimana (Fundi)—for overseeing the maintenance of high quality of data collection. Special thanks to Didier Abavandimwe for the creation of the interaction database specifically for this project and Damien Caillaud, for statistical support. Thank you to Martha Robbins and the reviewers for the constructive and insightful feedback that greatly improved the manuscript. We are very appreciative for the time and effort from Sarie Van Belle, Cyril Grueter, and Takeshi Furuichi to create this special issue. This project was funded by Cyril Grueter’s project grant (School of Human Sciences, University of Western Australia, grant number 10301036).

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Authors and Affiliations

  1. The University of Western Australia, Crawley, Australia

    Melanie O. Mirville, Amanda R. Ridley & Cyril C. Grueter

  2. The Dian Fossey Gorilla Fund International, Musanze, Rwanda

    J. P. M. Samedi, Veronica Vecellio, Felix Ndagijimana & Tara S. Stoinski

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  1. Melanie O. Mirville
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  2. Amanda R. Ridley
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  3. J. P. M. Samedi
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  4. Veronica Vecellio
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  7. Cyril C. Grueter
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CCG, MOM and ARR developed the idea, MOM, JPMS, VV, FN, TSS, CCG collected the data, MOM analyzed the data and wrote the manuscript; ARR, VV, TSS and CCG provided editorial advice.

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Correspondence to Melanie O. Mirville.

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Handling Editor: Takeshi Furuichi

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Mirville, M.O., Ridley, A.R., Samedi, J.P.M. et al. Intragroup Behavioral Changes Following Intergroup Conflict in Mountain Gorillas (Gorilla beringei beringei). Int J Primatol 41, 382–400 (2020). https://doi.org/10.1007/s10764-020-00130-1

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