When death comes: Linking predator-prey activity patterns to timing of mortality to understand predation risk

The assumption that activity and foraging are risky for prey underlies
many predator-prey theories and has led to the use of predator-prey
activity overlap as a proxy of predation risk. However, the simultaneous
measures of prey and predator activity along with timing of predation
required to test this assumption have not been available. Here, we used
accelerometry data on snowshoe hares (Lepus americanus) and Canada lynx
(Lynx canadensis) to determine activity patterns of prey and predators and
match these to precise timing of predation. Surprisingly, we found that
lynx kills of hares were as likely to occur during the day when hares were
inactive as at night when hares were active. We also found that activity
rates of hares were not related to the chance of predation at daily and
weekly scales, whereas lynx activity rates positively affected the diel
pattern of lynx predation on hares and their weekly kill rates of hares.
Our findings suggest that predator-prey diel activity overlap may not
always be a good proxy of predation risk, and highlight a need for
examining the link between predation and spatiotemporal behavior of
predator and prey to improve our understanding of how predator-prey
behavioral interactions drive predation risk.