Prey behavioural reaction norms: response to threat predicts susceptibility to predation

Behavioural syndromes (i.e. population-level behavioural correlations) arise when individuals, on average, maintain the same behavioural expression across different ecological contexts. Population-level syndromes can appear maladaptive, such as when prey remain active across the absence and presence of a sit-and-wait predator. Yet in nature, individuals often vary in syndrome adherence, exhibiting individual-level differences in behavioural plasticity. Here, I use an experiment to show that individual behavioural plasticity (a reduction in activity level in the presence of predation threat) increases a prey's likelihood of surviving predator exposure, and further predicts survival better than single-context activity level measures. In an additional experiment, I identify conditioning (nonlethal predator exposure) as a process that reduces prey activity level. This work demonstrates that although population-level behavioural syndromes can appear maladaptive, behavioural plasticity and conditioning could potentially ameliorate negative effects at the individual level.