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Abstract: In this paper, a three species food chain model, consisting of a hybrid type of prey-dependent and predator-dependent functional responses, is investigated analytically as well as numerically. The local and global stability analysis is carried out. The persistence conditions are established. Bifurcation diagrams are obtained for biologically feasible parameters. The results show that the system exhibits rich complexity features such as stable, periodic and chaotic dynamics. [Copyright &y& Elsevier]

Abstract: Synchronization is a natural phenomenon in non-linear dynamical systems. The relative importance of various mechanisms of population synchrony has been debated by population ecologists. The debate revolves around the issue whether the regionally extrinsic or locally intrinsic agents are more potent. In the present paper, we have attempted to demonstrate that a local intrinsic mechanism, predation, can be more common cause of population synchrony than is believed. Two chaotic food chains having different kinds of top-predators are synchronized using a recently proposed algorithm by Lu and Cao [Lu J, Cao J. Adaptive complete synchronization of two identical or different chaotic (hyperchaotic) dynamical systems with fully unknown parameters. Chaos 2005;15(043901):1–10]. The idiosyncracy of this approach is that it takes care of the uncertainties involved in the parameter estimation. The complete synchronization achieved is robust to noise present in the system. We suggest that local intrinsic causes of population synchrony should be given more attention. [Copyright &y& Elsevier]