Department of Collective Behaviour, Max Planck Institute of Animal Behavior, Konstanz, Germany; Zukunftskolleg, University of Konstanz, Konstanz, Germany; Centre for Ecological Research and Forestry Applications (CREAF), Barcelona, Spain
Matthew MG Sosna
Department of Ecology and Evolutionary Biology, Princeton University, Princeton, United States
Geoffrey PF Mazué
School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
Colin R Twomey
Department of Biology, University of Pennsylvania, Philadelphia, United States
Joseph Bak-Coleman
eScience Institute, University of Washington, Seattle, United States; Center for an Informed Public, University of Washington, Seattle, United States
Daniel I Rubenstein
Department of Ecology and Evolutionary Biology, Princeton University, Princeton, United States
Department of Collective Behaviour, Max Planck Institute of Animal Behavior, Konstanz, Germany; Department of Biology, University of Konstanz, Konstanz, Germany; Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
Predation is one of the main evolutionary drivers of social grouping. While it is well appreciated that predation risk is likely not shared equally among individuals within groups, its detailed quantification has remained difficult due to the speed of attacks and the highly dynamic nature of collective prey response. Here, using high-resolution tracking of solitary predators (Northern pike) hunting schooling fish (golden shiners), we not only provide insights into predator decision-making, but show which key spatial and kinematic features of predator and prey predict the risk of individuals to be targeted and to survive attacks. We found that pike tended to stealthily approach the largest groups, and were often already inside the school when launching their attack, making prey in this frontal ‘strike zone’ the most vulnerable to be targeted. From the prey’s perspective, those fish in central locations, but relatively far from, and less aligned with, neighbours, were most likely to be targeted. While the majority of attacks were successful (70%), targeted individuals that did manage to avoid being captured exhibited a higher maximum acceleration response just before the attack and were further away from the pike‘s head. Our results highlight the crucial interplay between predators’ attack strategy and response of prey underlying the predation risk within mobile animal groups.
