Analytical models for predator-prey contact and capture rates in turbulent environments
نویسنده
چکیده
Scaling laws for planktonic contact and capture rates in turbulent environments are obtained in terms of basic parameters for the problem. Enhanced turbulence levels increase the encounter rate but can, on the other hand, also be too large by reducing the capture probability. The results thus indicate an optimum intermediate turbulence level for the predator capture rate. Probability densities of some basic parameters entering the scaling laws were found by numerical simulations. We consider cases where the capture range of an organism is comparable to or smaller than the Kolmogorov length scale, as well as the opposite limit of large capture ranges. The reference model assumes spherical contact surfaces, but it is demonstrated that the results remain basically valid also for the case where the contact volumes are hemispherical or conical: the consequences of the conical shape can be accounted for by an empirical scaling factor, which depends solely on the opening angle of the cone.
منابع مشابه
Predator–prey encounter and capture rates in turbulent environments
Predator–prey encounter and capture rates are key drivers of population dynamics of planktonic organisms. Turbulent mixing gives rise to enhanced encounter rates, but high turbulence levels may reduce capture rates. We present an estimate for the optimum turbulence level for a predator that is characterized by a number of parameters, such as its range of interception. A limit at small spatial s...
متن کاملPredator–prey encounter rates in turbulent water: Analytical models and numerical tests
In aquatic environments the encounter rates between small predators and their prey are increased by turbulence. We present an expression for the flux of prey into the detective sphere of a small self-propelled predator. We then test this model by direct comparison of theoretical encounter rates with predictions from a numerical experiment where the Navier–Stokes equation is solved explicitly. T...
متن کاملThe Stability of Some Systems of Harvested Lotka-Volterra Predator-Prey Equations
Some scientists are interesting to study in area of harvested ecological modelling. The harvested population dynamics is more realistic than other ecological models. In the present paper, some of the Lotka-Volterra predator-prey models have been considered. In the said models, existing species are harvested by constant or variable growth rates. The behavior of their solutions has been analyzed ...
متن کاملThe Efficiency of Harvested Factor; Lotka-Volterra Predator-Prey Model
Scientists are interested in find out “how to use living resources without damaging the ecosystem at the same time?” from nineteen century because the living resources are limited. Thus, the harvested rate is used as the control parameters. Moreover, the study of harvested population dynamics is more realistic. In the present paper, some predator-prey models in which two ecologically inte...
متن کاملOptimal foraging in patchy turbulent environments
The problem of what strategy a predator should adopt when foraging in a turbulent and spatially patchy environment is investigated using simple mathematical models. The study was motivated by the need to understand the behaviour of marine fish larvae searching for copepod prey. It is demonstrated that optimal swimming speed should decrease with increasing turbulence, and that in a patchy turbul...
متن کامل