Individual behaviour, space and predator evolution promote persistence in a two-patch system with predator switching

Predator switching is often assumed to be a stabilizing force in predator–prey interactions. Recent models, however, have shown that predator switching can have a destabilizing effect on populations, creating cycles or even extinctions of predators and prey. However, most of these models have been traditional top-down mathematical models that do not incorporate individual variability or evolution. We explored the influence of predator switching on predator–prey stability, persistence and evolution using an individual-based, spatially explicit model of predators switching between two prey patches. We also created difference equation models for comparison with the simulations. We found that individual variability among predators, and selection acting on switching thresholds, helped in maintaining stability and persistence in our predator–prey system. Predators that estimated prey density (with error) or had ‘short memories’ produced more stable population dynamics than predators with perfect knowledge of prey density or had ‘long memories’. The threshold prey density at which switching occurred evolved in the predator population to be greater than the predicted optimal density. This result led to undermatching of predators to their resources and tended to increase predator–prey stability. Furthermore, multiple switching thresholds could be maintained in the predator population at the same time. These results suggest that in an ecological system with individual predators switching between prey species, predator switching may help stabilize predator–prey interactions.