How predator hunting-modes affect prey behaviour: Capture deterrence in Drosophila melanogaster

Abstract

Hunting mode, the distinct set of behavioural strategies that a predator employs while hunting, can be an important determinant of the prey organisms behavioural response. However, few studies have considered how a predators hunting mode influences anti-predatory behaviours of a prey species. Here we document the influence of active hunters (zebra jumping spiders, Salticus scenicus) and ambush predators (Chinese praying mantids, Tenodera aridifolia sinensis) on the capture deterrence anti-predatory behavioural repertoire of the model organism, Drosophila melanogaster. We hypothesized that D. melanogaster would reduce overall locomotory activity in the presence of ambush predators, and increase activity with active hunters. First we observed and described the behavioural repertoire of D. melanogaster in the presence of the predators. We documented three previously undescribed behaviours-abdominal lifting, stopping and retreat-which were performed at higher frequency by D. melanogaster in the presence of predators, and may aid in capture deterrence. Consistent with our predictions, we observed an increase in the overall activity of D. melanogaster in the presence of jumping spiders (active hunter). However, counter to our prediction, mantids (ambush hunter) had only a modest influence on activity. We also observed considerable intra and inter-individual variation in response to both predator types. Given these new insights into Drosophila behaviour, and with the genetic tools available, dissecting the molecular mechanisms of anti-predator behaviours may now be feasible in this system.