Recurrent intermittent rarity driven by adaptive dynamics
Rare species pose major challenges to population managers and conservation biologist. Such species can experience persistent periods of very low population size. Observation horizons are often so short compared to these periods that it is not clear whether species that we presently identify as rare have also been rare in the past and are likely to remain rare in the future. Resolving this issue requires insight into the ecological and evolutionary causes of rarity: population dynamics are determined by individual traits and these traits in turn are subject to natural selection. In this project I study a population model allowing for two alternative stable states, one of rarity and one of commonness, and analyze the implications of evolutionary adaptations for the long-term dynamics of the population. The results demonstrate that there are ecological conditions under which adaptive dynamics can induce recurrent switches between rarity and commonness.