Data from: Fear on the move: predator hunting mode predicts variation in prey mortality and plasticity in prey spatial response

1. Ecologists have long searched for a framework of a priori species
traits to help predict predator-prey interactions in food webs. Empirical
evidence has shown that predator hunting mode and predator and prey
habitat domain are useful traits for explaining predator-prey
interactions. Yet individual experiments have yet to replicate predator
hunting mode, calling into question whether predator impacts can be
attributed to hunting mode or merely species identity. 2. We tested the
effects of spider predators with sit-and-wait, sit-and-pursue and active
hunting modes on grasshopper habitat domain, activity and mortality in a
grassland system. We replicated hunting mode by testing two spider
predator species of each hunting mode on the same grasshopper prey
species. We observed grasshoppers with and without each spider species in
behavioral cages and measured their mortality rates, movements and habitat
domains. We likewise measured the movements and habitat domains of spiders
to characterize hunting modes. 3. We found that predator hunting mode
explained grasshopper mortality and spider and grasshopper movement
activity and habitat domain size. Sit-and-wait spider predators covered
small distances over a narrow domain space and killed fewer grasshoppers
than sit-and-pursue and active predators, which ranged farther distances
across broader domains and killed more grasshoppers, respectively. Prey
adjusted their activity levels and horizontal habitat domains in response
to predator presence and hunting mode: sedentary sit-and-wait predators
with narrow domains caused grasshoppers to reduce activity in the
same-sized domain space; more mobile sit-and-pursue predators with broader
domains caused prey to reduce their activity within a contracted
horizontal (but not vertical) domain space; and highly mobile active
spiders led grasshoppers to increase their activity across the same domain
area. All predators impacted prey activity and sit-and-pursue predators
generated strong effects on domain size. 4. This study demonstrates the
validity of utilizing hunting mode and habitat domain for predicting
predator-prey interactions. Results also highlight the importance of
accounting for flexibility in prey movement ranges as an anti-predator
response rather than treating the domain as a static attribute.