Predator–prey systems depend on a prey refuge

• The underlying causes of predator–prey population dynamics are not fully understood.
• Existing models of predator–prey systems include factors such as sea sonal effects.
• No model to date has reproduced all six patterns evident in exclusive systems.
• Our model reproduces all six empirical patterns without the factors of other models.
• An exclusive predator–prey system can persist if the prey have a refuge.

Models of near-exclusive predator–prey systems such as that of the Canadian lynx and snowshoe hare have included factors such as a second prey species, a Holling Type II predator response and climatic or seasonal effects to reproduce sub-sets of six signature patterns in the empirical data. We present an agent-based model which does not require the factors or constraints of previous models to reproduce all six patterns in persistent populations. Our parsimonious model represents a generalised predator and prey species with a small prey refuge. The lack of the constraints of previous models, considered to be important for those models, casts doubt on the current hypothesised mechanisms of exclusive predator–prey systems. The implication for management of the lynx, a protected species, is that maintenance of an heterogeneous environment offering natural refuge areas for the hare is the most important factor for the conservation of this species.