Mate location, population growth and species extinction

The effects of mate location efficiency on the dynamics of population growth and extinction were modeled with a view towards future species conservation efforts. Mate location is shown to be based on the Allee principle. Higher population densities produce greater mate location success rates. Low population densities generate population growth rates that are smaller than mortality rates, and, thus, produce a condition leading to species extinction. A survey of animal phyla suggests that selection for behaviors, morphology and physiology, which either temporarily increase mating season population densities or effectively increase population densities by increasing the distance from which a mate can be recognized, has shaped the evolution of species. A mechanism is provided for understanding this process of extinction, and a framework is presented for constructing a management plan for species at risk. (C) 1998 Elsevier Science Ltd. All rights reserved.