title: Delayed population models with Allee effects and exploitation.
abstract: Allee effects make populations more vulnerable to extinction, especially under severe harvesting or predation. Using a delay-differential equation modeling the evolution of a single-species population subject to constant effort harvesting, we show that the interplay between harvest strength and Allee effects leads not only to collapses due to overexploitation; large delays can interact with Allee effects to produce extinction at population densities that would survive for smaller time delays. In case of bistability, our estimations on the basins of attraction of the two coexisting attractors improve some recent results in this direction. Moreover, we show that the persistent attractor can exhibit bubbling: a stable equilibrium loses its stability as harvesting effort increases, giving rise to sustained oscillations, but higher mortality rates stabilize the equilibrium again.
authors: Departamento de Matematica Aplicada II, E.T.S.E. Telecomunicacion, Universidade de Vigo, Campus Marcosende, 36310 Vigo, Spain. eliz@dma.uvigo.es.
authors: Eduardo
authors: E
authors: Liz
authors: Alfonso
authors: A
authors: Ruiz-Herrera
mesh_terms: D000465:Algorithms; D000818:Animals; D003198:Computer Simulation; D017753:Ecosystem; D053476:Extinction, Biological; D008954:Models, Biological; D009991:Oscillometry; D011156:Population Density; D011157:Population Dynamics; D011235:Predatory Behavior; D013997:Time Factors