A review of two recent predation-rate models : The dome-shaped relationship between feeding rate and shear rate appears universal

Two predation-rate models are reviewed: one, a stochastic model by MacKenzie et al. (1994) applies to the scales of intermediate and fully turbulent deformation; the other, a deterministic model by Jenkinson and Wyatt (1992) applies to the scales of laminar shear. Both models predict that predation rate should be a dome-shaped function of deformation rate. This is because, above a given deformation rate, some of the prey entering the model predator's perception zone (reactive field) is carried out of perception distance (reactive distance) again before the predator can catch it. Using the concept of the Deborah number, it is shown that both models agree well at the interface between their respective domains. This adds credibility to both models and suggests that the dome-shaped function applies across all scales.