Disease-selective predation may lead to prey extinction

In real world bio-communities, predational choice plays a key role to the persistence of the prey population. Predator's 'sense' of choice for predation towards the infected and noninfected prey is an important factor for those bio-communities. There are examples where the predator can distinguish the infected prey and avoids those at the time of predation. Based on the examples, we propose two mathematical models and observe the dynamics of the systems around biologically feasible equilibria. For disease-selective predation model there is a high risk of prey extinction. On the other hand, for non-disease selective predation both populations co-exist. Local stability analysis and global stability analysis of the positive interior equilibrium are performed. Moreover, conditions for the permanence of the system are obtained. Finally, we conclude that strictly disease-selective predation may not be acceptable for the persistence of the prey population. Copyright (C) 2005 John Wiley & Sons, Ltd.