Abstract
Demographic, genetic and environmental factors such as predation determine whether small and fragmented populations may persist. Many recent studies have highlighted the importance of genetics. Most threatened taxa show low levels of genetic diversity, suggesting reduced reproductive fitness (e.g. due to inbreeding depression) and elevated extinction risk. However, translocation experiments with mammals, birds and reptiles have demonstrated that introduction of new genes can rescue genetically impoverished populations from extinction. In a current project supported by Formas, I have examined population dynamics and genetic variability in a fragmented population of southern dunlins (Calidris alpina schinzii), a threatened wader species. This study has documented a high extinction rate of local populations, substantial loss of genetic diversity, and reduced offspring fitness due to increased frequency of matings between related individuals. In this new project, I propose to (1) further examine the influence of genetic diversity and predation on small and threatened populations, and (2) test whether the current negative trends can be halted or perhaps even reversed. Combining a unique long-term data set with a series of new experiments (including introduction of new genes), the study will produce knowledge that is vital for preserving dunlins and other indicators of biodiversity in the agricultural landscape.
Sweden