Conspecific boldness and predator species determine predation-risk consequences of prey personality
Individual variation in the behavior of prey can influence predation risk in complex ways. We ran individual roach (Rutilus rutilus), a common freshwater fish, through a standard refuge emergence protocol to characterize their boldness, a key animal personality trait. We then paired a bold and a shy roach and exposed the pair to one of two predator species that have contrasting hunting modes to ascertain how personality traits shaped their survival during predator encounters. When a paired bold and shy prey fish interacted with a perch predator (active foraging mode), bold and shy prey were consumed in almost equal numbers. However, pike predators (ambush foraging mode) selectively consumed more shy prey, and prey body size and boldness score both contributed significantly to which prey fish was eaten. Our findings support the idea that multiple predators with different foraging modes, and hence differential selection on prey personality, could contribute to maintaining variation in personality in prey populations. Furthermore, for social species, including shoaling fish, the ultimate consequences of an individual’s personality may depend upon the personality of its nearby conspecifics.
Animals of the same species often look similar, but individuals show differences in their behavior that can have important consequences, for instance when these individuals interact with predators. The common roach is a freshwater fish that shows inter-individual variation in its propensity to take risks, a key personality trait often termed boldness. Variation in boldness may affect the outcome when roach interact with predators, i.e., if they get eaten or survive. However, we found the impact of roachs’ personality type depends on what species of predatory fish they face. When we put a shy and a bold roach together with predatory perch, the roachs’ personality did not significantly affect which individual was eaten. But when the predator was a pike, the predators selectively ate more shy roach, and the likelihood an individual would be eaten depended on their body size.
KeywordsPredator-prey interactions Behavioral type Boldness Social context
We thank Lars-Anders Hansson for participating in preparing the grant application and developing research ideas. We thank Marek Šmejkal and Jerker Vinterstare for help with field work and methodology. We acknowledge Caitlin Gabor for her mentorship of C.A. Blake, and Augustyn Blake for his continued support. We are grateful to the entire Aquatic Ecology Unit at Lund University for their feedback on the project. Finally, we thank two anonymous reviewers and the editor, whose suggestions helped us greatly improve the manuscript.
We thank the National Science Foundation for providing a grant through Graduate Research Opportunities Worldwide to C.A. Blake to support travel and supplies for collaborative research at Lund University.
Compliance with ethical standards
All applicable international, national, and/or institutional guidelines for the care and use of animals were followed. All procedures performed in studies involving animals were in accordance with the ethical standards of the institution or practice at which the studies were conducted. Experiments were performed under permission from the Lund/Malmö Ethical Committee (permission number M36-14).
Conflict of interest
The authors declare that they have no conflict of interest.
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