Identifying the mechanisms of prey switching in terrestrial wildlife: A protocol for a systematic literature review

Abstract

Predators switch prey when they alter their consumption towards a prey species in a manner that is disproportionately greater than would be expected when the prey species is highly abundant and disproportionately lower than expected when the prey species is at low abundance. Prey switching can stabilize populations, simultaneously inhibiting both extinction and overpopulation of prey and predators. However, prey switching is not universal in multi-prey systems, with some predators preferring one prey species regardless of its relative abundance. With the implications for conservation and management, predator diet selection has been studied across diverse systems. Here, we harness the abundance of literature and conduct a systematic review to determine the occurrence of prey switching in nature and to identify the factors and conditions which produce changes in prey preferences. We will test for relationships between relative prey densities and relative consumption rates to identify a ‘tipping point’ at which predators switch prey. We will determine factors which influence this relationship, such as taxa, sociality, species biomass, ecosystem productivity, and predator condition and identity. Practical implication. Disentangling when and why prey switching occurs will significantly impact conservation, ecosystem management and human–wildlife conflicts.