System Dynamics Investigation of Genetic Drift and Translocation in the Red-Cockaded Woodpecker Metapopulation.

摘要

The red-cockaded woodpecker (Picoides borealis) is classified under the Endangered Species Act of 1973 as an endangered species As such, the red- cockaded woodpecker (RCW) is afforded strict protection in an effort to return the RCW population to a self-sustainable level. Endemic to southeastern United States mature pine forests, the presence of the RCW impacts the operations of many Department of Defense (DoD) installations. A particular challenge in sustaining what are often small populations of RCW at these locations is the loss of genetic variation due to genetic drift. The optimal method for mitigating such loss is through the artificial immigration, termed translocation, of individual RCWs from other populations. The research objective of this effort was to quantify the translocation rate that would counter genetic drift in small populations though the modeling of RCW populations using a system dynamics approach, Both source and target populations utilizing various magnitudes and frequencies of translocations were modeled over a time period of 50 generations. While the optimal translocation rate is dependent on the initial population size, the results of this research indicate that it is possible to counter the effects of genetic drift in RCW populations as small as 10 mating pairs with the translocation of two pairs of red- cockaded woodpeckers twice per generation.