The response of social and non-social rodents to owl attack

Abstract

Studies with individual rodents have revealed that they display protean (unpredictable) behavior when attacked by an owl. Other studies have revealed that voles in groups reduce behavioral variability a short time after owl attack, as if adopting the behavior of the higher-mass and perhaps older and more experienced, individuals. Here, we tested groups of rodents under owl attack in order to track the behavior of individuals within the group and compare between the behaviors of social and non-social species. We found differential behavior between species, between groups of the same species, among individuals in the same group, and among the various phases of the owl attack. We also found that upon being exposed to an owl, social rodents tended to huddle together whereas solitary rodents tended to scatter across the available space. Other non-social but perhaps not necessarily solitary rodent species displayed a mixed spacing, with some huddling and some scattering. The findings of the present study shed light on the defensive dynamics of small groups of social and non-social rodent species when they were under owl attack. Freezing and fleeing are defensive responses that span the animal kingdom, and rodents display various combinations of these in order to prevent predators from predicting their response. Groups of six voles or six spiny mice that were attacked by a barn owl differentially displayed these responses during various phases of the owl attack. Responses also varied among individuals of the same group and among different groups. Finally, we show that when exposed to an owl and displayed freeze response, individuals of social species tended to huddle together, whereas individuals of solitary species scattered over the arena.