Pollinator-induced density dependence in deceptive species

Many animal-pollinated species experience low visitation rates and, in some cases, stand on the brink of extinction because they are poorly fertilized . Among these plants, some are deceptive species (flowering plants that do not offer any reward to their pollinators). A learning process that pollina tors undergo determines visitation rate in those food frauds that do not mi mic rewarding models. Pollinators that visit cheating species avoid them af ter having experienced the absence of reward a few times and then visit rew arding plants. We modeled this learning process, using classical optimal fo raging and game theory tools, and applied our model to survey how visitatio n rate can be adjusted in deceptive species in a density-dependent way and how it can influence the population dynamics of those species. We found pol linator behavior to induce positive density dependence at low density (Alle e effect) and therefore to create a threshold density under which populatio n survival is not possible. Moreover, negative density dependence occurs at high density so that in most cases pollination limitation creates a stable demographic equilibrium. Stochastic simulations were performed to investig ate the stability of populations at these equilibria and estimate their mea n time to extinction. Because some parameters such as pollinator density or habitat fragmentation were explicitly taken into account, we tried to desc ribe environmental conditions conducive to a deceptive plant's survival.