Behavioural synchronization in a multilevel society of feral horses

Behavioural synchrony among individuals is essential for group-living
organisms to maintain their cohesiveness necessary to get information and
against predation. It is still largely unknown how synchronization
functions in a multilevel society, a nested assemblage of multiple social
levels between many individuals. Our aim was to build a model to explain
the synchronization of activity in a multilevel society of feral horses.
We used multi-agent based models based on four hypotheses: A) independent
model: horses do not synchronize, B) anonymous model: horses synchronize
with any individual in any unit, C) unit-level social model: horses
synchronize only within units and D) herd-level social model: horses
synchronize across and within units, but internal synchronization is
stronger. We simulated each model 100 times and compared simulations to
the empirical data obtained from drone observations. The hypothesis D best
supported empirical data. This result suggests that synchronization
occurred at an intra- and inter-unit level.