Does trapping catch sociable, exploratory and innovative mynas preferentially? No, but perhaps less fearful ones

Humans prey on animals with often dramatic effects on abundances, but also alterations to the phenotypical composition of prey populations. Instances of lethal management provide an opportunity to explore proximate mechanisms of phenotypical change. While there is evidence from exploitative predation (e.g. fisheries) that prey can change via evolutionary mechanisms, we present one of the first studies to explore this effect in an invasive vertebrate species that is being lethally controlled. Using an avian species that is known to be changing its behaviour in areas where it is heavily trapped, this study explored whether trapping of specific behavioural phenotypes might underpin observed changes. The behaviour of common mynas, Acridotheres tristis, captured using a large walk-in baited trap was compared with that of mynas captured using a cryptic whoosh net. All tests revealed significant inter-individual variation in ecologically meaningful aspects of myna temperament. Contrary to our predictions, however, we found no evidence that mynas captured in traps were more exploratory, more sociable, less fearful or better problem-solvers than those captured with the cryptic net. We present various interpretations of this finding, including the possibility learning might underpin behavioural changes in free-ranging mynas from heavily trapped populations, complemented by some selection against sociability and low fearfulness. As such, our findings and their interpretation will serve to guide future research on prey responses to human predation and inform animal management practices.