Both Nearest Neighbours and Long-term Affiliates Predict Individual Locations During Collective Movement in Wild Baboons.
In many animal societies, groups of individuals form stable social units that are shaped by well-delineated dominance hierarchies and a range of affiliative relationships. How do socially complex groups maintain cohesion and achieve collective movement? Using high-resolution GPS tracking of members of a wild baboon troop, we test whether collective movement in stable social groups is governed by interactions among local neighbours (commonly found in groups with largely anonymous memberships), social affiliates, and/or by individuals paying attention to global group structure. We construct candidate movement prediction models and evaluate their ability to predict the future trajectory of focal individuals. We find that baboon movements are best predicted by 4 to 6 neighbours. While these are generally individuals' nearest neighbours, we find that baboons have distinct preferences for particular neighbours, and that these social affiliates best predict individual location at longer time scales (>10 minutes). Our results support existing theoretical and empirical studies highlighting the importance of local rules in driving collective outcomes, such as collective departures, in primates. We extend previous studies by elucidating the rules that maintain cohesion in baboons 'on the move', as well as the different temporal scales of social interactions that are at play.
Department of Anthropology, University of California Davis, 1 Shields Avenue, Davis CA, USA.|Smithsonian Tropical Research Institute, Balboa, Panama.|Edward Grey Institute of Field Ornithology, Department of Zoology, University of Oxford, South Parks Road, Oxford, UK.|Department of Collective Behaviour, Max Planck Institute for Ornithology, Konstanz, 78457, Germany.|Department of Biology, University of Konstanz, 78457, Germany.
Damien R
DR
Farine
Department of Ecology and Evolutionary Biology, Princeton University, 106A Guyot Hall, Princeton, NJ, USA.
Ariana
A
Strandburg-Peshkin
Department of Computer Science, University of Illinois at Chicago, 851 South Morgan St, Chicago IL, USA.
Tanya
T
Berger-Wolf
Department of Computer Science, University of Illinois at Chicago, 851 South Morgan St, Chicago IL, USA.
Brian
B
Ziebart
Department of Computer Science, University of Illinois at Chicago, 851 South Morgan St, Chicago IL, USA.
Ivan
I
Brugere
Department of Computer Science, University of Illinois at Chicago, 851 South Morgan St, Chicago IL, USA.
Jia
J
Li
Department of Anthropology, University of California Davis, 1 Shields Avenue, Davis CA, USA.|Smithsonian Tropical Research Institute, Balboa, Panama.|Animal Behaviour Graduate Group, University of California Davis, 1 Shields Avenue, Davis CA, USA.
Margaret C
MC
Crofoot
D000818:Animals; D001522:Behavior, Animal; D005260:Female; D040362:Geographic Information Systems; D008297:Male; D009068:Movement; D010215:Papio / Q000502:physiology*; D012919:Social Behavior; D012930:Social Dominance