Vertical Diversity (Stratification) & Snags

2. Vertical Diversity (Stratification) & Snags

3. The Niche • Species differ in the breadth of their niche, • euryphagous = wide diet • stenophagous = narrow diet • generalists vs. specialists

4. ecotones, coverts, edges The “Edge Effect”

5. habitat interspersion – Leopold’s Law of Interspersion

6. Habitat Fragmentation 1) gap formation 2) decrease patch size 3) increase isolation 4) increase edge 5) conversion of matrix

7. Countering Edge Effects & Habitat Fragmentation • Develop connectivecorridors • Increase edgecomplexity

8. Roads: Formation of Barriers in Landscapes

11. Animal Movements • Concept of the homerange - refers to the minimum area needed for an individual to meet all of its normal life requirements • any part of a home range that is defended intra-specifically, is a territory • (reducing competition, population regulation, spread risk)

14. Animal Movements Types: • Dispersal = 1-way movement (emmigrant vs. immigrant) - typically includes juveniles leaving natal home range

17. Animal Movements Types: • Dispersal = 1-way movement (emmigrant vs. immigrant) - typically includes juveniles leaving natal home range 2)Migration = round-trip movement - altitudinal & latitudinal; movement to breeding and wintering grounds

19. Mortality • Predation • Habitat Loss • Disease (e.g. bovine tuberculosis, botulism, pollutants) • Hunting & Trapping

20. Mortality Types: 1) additive mortality: mortality factors interact in additive manner e.g., hunting mortality + mortality from predation 2) compensatory mortality: total mortality unchanged despite multiple mortality factors… “mortality factors offset one another” e.g., less disease mortality with increased hunting harvestable surplus

21. Managing Overabundant Wildlife • Canada goose • Resident, giant Canada geese (“golf course geese”) • Complaints, disease

22. Managing Overabundant Wildlife Canada goose * harvest controlled by: - length of season - bag limits - hunting dates - harvest quotas * Michigan Canada geese = 1) Mississippi Valley Population (MVP) 2) Southern James Bay Population (SJBP) 3) local giant Canada geese (early/late hunt) (“golf-course geese”)

25. Early Season Regular Season Late Season

27. Biodiversity Hotspots Check link on BIO 240 Web Page --- learn about different sites around the world

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

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

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

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

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

33. 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

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

35. Wildlife Reintroductions • Genetic Considerations • Founder Effect

36. 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

37. Wildlife Reintroductions • Genetic Considerations • Genetic Bottleneck

38. 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

39. 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

40. 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)

41. Different Colors Represent Copies of Different Genes Hypothetical SourcePopulation

42. 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

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

44. 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

45. 20 Generation Bottleneck 20 Genetic Drift Loss of Allelic Diversity Apparent Inbreeding Intermediate BOTTLENECK

46. 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

47. Wildlife Reintroductions • Genetic Considerations • Marten reintroductions