Simulation modeling of population viability for the leopard darter (Percidae: Percina pantherina)

We used the computer program RAMAS to perform a population viability analysis for the leopard darter, Percina pantherina. This percid fish is a threatened species confined to five isolated rivers in the Ouachita Mountains of Oklahoma and Arkansas. A base model created from life history data indicated a 6% probability that the leopard darter would go extinct in 50 years. We performed sensitivity analyses to determine the effects of initial population size, variation in age structure, variation in severity and probability of catastrophe, and migration rate. Catastrophe (modeled as the probability and severity of drought) and migration had the greatest effects on persistence. Results of these simulations have implications for management of this species.