‘Let’s stick together,’
said the guppy to her friend,
‘we can swim in step.’
Shoaling in fish can provide safety from predators and increase the effectiveness of group movement. This group efficiency can be influenced by the behaviour of individuals within the group and a measure of group coordination is the extent to which animals align with one another – termed polarisation.
Investigating female guppies, Davis et al (2017) found that groups of familiar individuals were more polarised than groups of unfamiliar individuals. This was especially apparent when the groups were in novel surroundings and reduced with habituation to their surroundings. This increased coordination suggests that groups of individuals familiar with one another may be better able to cope with challenging situations.
Original research: https://doi.org/10.1098/rsos.170312