Data from: Quantifying uncertainty due to fission-fusion dynamics as a component of social complexity

Groups of animals (including humans) may show flexible grouping patterns,
in which temporary aggregations or subgroups come together and split,
changing composition over short temporal scales, i.e. fission and fusion).
A high degree of fission-fusion dynamics may constrain the regulation of
social relationships, introducing uncertainty in interactions between
group members. Here we use Shannon's entropy to quantify the
predictability of subgroup composition for three species known to differ
in the way their subgroups come together and split over time: spider
monkeys (Ateles geoffroyi), chimpanzees (Pan troglodytes) and geladas
(Theropithecus gelada). We formulate a random expectation of entropy that
considers subgroup size variation and sample size, against which the
observed entropy in subgroup composition can be compared. Using the theory
of set partitioning, we also develop a method to estimate the number of
subgroups that the group is likely to be divided into, based on the
composition and size of single focal subgroups. Our results indicate that
Shannon's entropy and the estimated number of subgroups present at a
given time provide quantitative metrics of uncertainty in the social
environment (within which social relationships must be regulated) for
groups with different degrees of fission-fusion dynamics. These metrics
also represent an indirect quantification of the cognitive challenges
posed by socially dynamic environments. Overall, our novel methodological
approach provides new insight for understanding the evolution of social
complexity and the mechanisms to cope with the uncertainty that results
from fission-fusion dynamics.