Data from: A predation cost to bold fish in the wild

Studies of predator-mediated selection on behaviour are critical for our
understanding of the evolution and maintenance of behavioural diversity in
natural populations. Consistent individual differences in prey behaviour,
especially in the propensity to take risks (“boldness”), are widespread in
the animal kingdom. Theory predicts that individual behavioural types
differ in a cost-benefit trade-off where bolder individuals benefit from
greater access to resources while paying higher predation-risk costs.
However, explicitly linking predation events to individual behaviour under
natural conditions is challenging and there is currently little data from
the wild. We assayed individual behaviour and electronically tagged
hundreds of fish (roach, Rutilus rutilus) before releasing them into their
lake of origin, thereby exposing them to predation risk from avian apex
predators (cormorants, Phalacrocorax carbo). Scanning for regurgitated
tags at the cormorant roosting site provided data on individual predation
events. We found that fish with higher boldness have a greater
susceptibility to cormorant predation compared to relatively shy,
risk-averse individuals. Our findings hereby provide unique and direct
evidence of behavioural type-dependent predation vulnerability in the
wild, i.e. that there is a predation cost to boldness, which is critical
for our understanding of the evolution and maintenance of behavioural
diversity in natural populations.