sDiscrete reproduction leads to an intermediate predator-prey functional response

摘要

Prey-dependent functional responses in which the number of prey consumed per predator depends solely on the density of prey (LOTKA 1925, VOLTERRA 1926, HOLLING 1959, ROSENZWEIG & MACARTHUR 1963), and ratio-dependent functional respons-es (Mum & GINZBURG 1989) in which the number of prey consumed per predator are a function of the ratio of prey to predators, arc extremes (ABRAMS & GINZBURG 2000). GINZBURG & JENSEN (2007) suggested that "prey sharing" should lead to an intermediate functional response that approaches ratio-de-pendence when predator density is high and prey-dependence when predator density is low. Simulations by TYUTYUNOV et al. (in review) confirm such a functional response. We elaborate the idea of prey sharing by discussing its 2 components and the functional responses mechanistically derived from them. The resulting function should generalize prey- and ratio-dependence, as well as produce intermediate forms.