Reintroductions & Translocations

1. Reintroductions & Translocations Continue to be an important tool in wildlife management

2. Wildlife Reintroductions • Does habitat remain? • How much? • Connected? • Management? • Competition / Predation / Diseases

3. Wildlife Reintroductions • Viable Population? • PVA • VORTEX • RAMAS

4. Wildlife Reintroductions • Viable Population? • PVA • VORTEX • RAMAS • Incorporate GIS

5. Wildlife Reintroductions • Genetic Considerations – Why should you care? • Genetic swamping?

6. Genetic Considerations: Why Should You Care? • Genetic variation is the underlying basis for adaptation to future environmental change • Loss of genetic variation is often a direct consequence of species reintroduction • Understanding how genetic loss occurs can help to prevent management actions that decrease the genetic diversity of reintroduced wildlife species

7. Wildlife Reintroductions • Genetic Considerations • Inbreeding • Did we release highly related individuals?

8. Wildlife Reintroductions • Genetic Considerations • Founder Effect

9. Founder Effect • The reduction in overall genetic diversity experienced as a consequence of population establishment from a limited sample of individuals • Most reintroductions and natural colonization events exhibit Founder Effects • The magnitude of the effect depends upon the number of animals translocated or colonizing an area

10. Wildlife Reintroductions • Genetic Considerations • Genetic Bottleneck

11. Bottleneck • An event in which a population drops significantly in size and then recovers • Events such as habitat loss, over harvest, or reintroduction can create bottlenecks and the magnitude of the effect on genetic diversity depends upon: • Number of individuals at lowest point • Length of time population remains depressed

12. Genetic Drift • Random fluctuations in gene frequencies due to temporal variance in survival and reproduction • Small populations drift more rapidly than large ones • Higher reproductive and survival rates can slow the rate of genetic drift • Genetic drift can result in loss of genetic diversity as well as increases in the frequency of rare alleles

13. Inbreeding • Mating of closely related individuals • Anytime genes that are alike by descent (i.e., from a shared ancestor) come together within individuals • Enhanced by slow population growth rates • Affected by mating system • Influenced by the relatedness of the initial population founders (e.g. reintroductions)

14. Different Colors Represent Copies of Different Genes Hypothetical SourcePopulation

15. Trap and Transplant Reintroduced Population SAMPLING ERROR Loss of Alleles Due to Original Sampling Event • Small Samples From Source • Incomplete Sampling of Genes • Sampling of Related Groups

16. Founder Effects FOUNDER EFFECTS Loss of Alleles Due to Post-Release Stochastic Processes • Differential Survival of Founders • Differential Survival of Offspring • Differential Reproductive Contributions

17. 10 10 Generation Bottleneck Genetic Drift Inbreeding Loss of Alleles Due to Stochastic And Deterministic Processes Over Generations • Inefficient Transfer of Genes • Unequal Reproductive Contributions • Differential Survival • Mating of Closely Related Individuals Brief BOTTLENECK

18. 20 Generation Bottleneck 20 Genetic Drift Loss of Allelic Diversity Apparent Inbreeding Intermediate BOTTLENECK

19. 30 30 Generation Bottleneck Genetic Drift Inbreeding Loss of Allelic Diversity Dramatic Common Allele Predominant Loss of Allelic Diversity Dramatic Rare Allele Predominant Prolonged BOTTLENECK

20. Wildlife Reintroductions • Genetic Considerations • Marten reintroductions