How population dynamics change in presence of migratory prey and predator's preference

We have studied changes in the dynamics of a predator population, which otherwise lives on a native prey, in presence of migratory prey that carries some infection. Our study predicts one of the four behaviors when some system parameters were varied: eradication of the disease, predator extinction, coexistence at stable equilibrium, or coexistence on limit cycles. If predator prefers susceptible prey then the input rate of migratory prey should be low to have a disease-free stable state. The disease-free equilibrium remains stable, even at higher input rate of migratory prey, if predator strongly prefers infected prey. All the species coexist either in stable or oscillatory state at higher infection rate; but the system remains in disease-free state at lower infection rate when predator strongly prefers infected prey. If predator prefers susceptible prey then the disease remains endemic for both higher and lower infection rates. The predator population, on the other hand, may go to extinction if its growth from the native prey is low. The observation may be fruitful in designing the management strategy for the disease caused by migratory birds.

► The study revealed that a predator–prey system in the presence of infection and migration, may exhibit variety of dynamics, but the precise outcome of the interaction depends on the life history parameters of host and predator populations.
► If predator prefers susceptible prey then the input rate of migratory prey should be low to have a disease-free system. On the other hand, the system remains disease-free, even at higher input rate of migratory prey, if predator prefers infected prey.
► If predator prefers susceptible prey then the disease remains endemic for both higher and lower infection rates.
► Predator may go to extinction if its growth rate from naive prey is too low.
► It is important to take necessary preventive measures using the in-built system controls like disease contact rate, migration rate, predator selectivity etc. with the prior knowledge of the disease dynamics.