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Subbey, S.

Publications and source records attributed to Subbey, S..

2 recordsLinked to original sources

Population Dynamic Regulators In An Empirical Predator-Prey System

This paper investigates stability conditions of an empirical predator-prey system using a model that includes a single delay term,{tau} , in description of the predator dynamics. We derive theoretical conditions on{tau} , in terms of other model parameters, and determine how changes in these conditions define different stability regimes of the system. We derive optimal model parameters by fitting model to empirical data, using unconstrained optimization. The optimization results are combined with those from the theoretical analysis, to make inference about the empirical system stability. Our results show that Hopf bifurcation occurs in the predatory-prey system when{tau} exceeds a theoretically derived value{tau} * > 0. This value represents the critical time for prey availability in advance of the optimal predator growth period. Set into an ecological context, our findings provide mathematical evidence for validity of the match-mismatch hypothesis, for this particular species.

ecology

Crowding Effects In An Empirical Predator-Prey System

AO_SCPLOWBSTRACTC_SCPLOWThis paper uses a Lotka-Volterra (predator-prey) modeling framework to investigate the dynamical link between the biomass of an empirical predator, and that of its prey. We use a system of ordinary (ODE) differential equations to describe the system dynamics, and derive theoretical conditions for stability, in terms of system parameters. We derive the empirical system parameters by fitting the ODE system to empirical data, using non-constrained optimization. We present results to show that the predator biomass is regulated by that of the prey. Furthermore, that the system dynamics is subject to Hopf bifurcation, conditioned on independent second-order terms in the ODE system. In ecological terms, the findings translate into evidence for existence of population crowding (density) effects.

ecology