The rules of baboons: Biologists study the principles underlying the collective movement of baboons

Date: May 30, 2017
Source: University of Konstanz

How do baboons succeed in coordinating the movements of their group? Biologists at the University of Konstanz study these organisms in the wild to find out which behavioural rules baboons use when interacting with others. Konstanz researchers have found out that the animals only need a few simple rules to coordinate their group movements, enabling them to organise themselves, and to make decisions, without splitting. In four recent research publications -- published in the journals Science, Scientific Reports, eLife and the Proceedings of the Royal Society B -- the Konstanz scientists paint a new picture of group dynamics among baboons with unprecedented detail by tracking how individuals make decisions within a group. Research partners were the Max Planck Institute for Ornithology, the Smithsonian Tropical Research Institute in Panama as well as Princeton University, the University of California, Davis, and the University of Illinois at Chicago (all USA).

Baboons have long been studied because they have a highly complex social structure, forming groups from 20 to over 100 individuals. Such social structure suggested to early biologists that baboons must employ high levels of cognition to be able to coordinate their behaviour with so many group mates. For example, classical theories on group coordination among baboons suggested that the larger, grown-up individuals should stay at the periphery of the group to protect younger and weaker animals in the centre. However, to constantly keep up this positioning, each baboon would need to know, at all times, where the other members of the group are. Konstanz biologists have now demonstrated that this is not necessarily the case -- neither is there a need for it. "Actually, coordinating their movement with only a few neighbouring individuals can generally be enough for animals to keep their group together, and what we see in the baboons is consistent with this idea," explains biologist Dr. Ariana Strandburg-Peshkin. Mathematics can further explain how individuals maintain specific positions within the group (either close to the center, at the front, back, or at the periphery) as her colleague Dr. Damien Farine explains: "If a baboon tries to stay together with only a slightly larger number of neighbouring individuals, this baboon will automatically move closer to the centre of the group. By contrast, individuals that coordinate their positions with a smaller number of fellow group members will end up at the group's periphery."



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Majority rules when baboons vote with their feet

Date:June 18, 2015

Source:Smithsonian Tropical Research Institute

Summary:Olive baboon troops decide where to move democratically, despite their hierarchical social order, according to a new report. At the Mpala Research Centre in Kenya, biologists conducted the first-ever group-level GPS tracking study of primates, finding that any individual baboon can contribute to a troop's collective movement.

'Despite their social status, it's not necessarily the biggest alpha males that influence where groups go,' said Margaret Crofoot, research associate at Smithsonian Tropical Research Institute (STRI) and assistant professor of anthropology at University of California, Davis (UC Davis). 'Our observations suggest that many or all group members can have a voice, even in highly stratified societies.'

Wild olive baboons (Papio anubis) live in strongly hierarchical troops. Dominant individuals displace subordinates when feeding or mating. However, analyzing the second-by-second GPS trajectories of each individual in a single troop revealed that neither a baboon's rank nor their sex conferred leadership ability. Much to the scientists' surprise, what emerged was almost identical to patterns previously predicted by theoretical models based on the movements of fish schools, bird flocks and insect swarms. Decision making in baboons is largely a shared process: individuals vote with their feet by choosing to lead or follow their troop-mates.

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