Imperiled Populations II

1. Imperiled Populations II 10 Sept 2009

2. Pacific Walrus- under review for ESA listing -

3. Pacific Walrus- under review for ESA listing - What would you do? Pinchot Muir Leopold

4. Demographic Stochasticity Random fluctuations in demographic parameters (birth & death rate, immigration & emigration rate, sex ratios, or age structure). Allee effects become increasingly problematic at small population sizes: probability of encountering mates communal mating activity cooperative/group defense & hunting success communal insulation & nesting

5. Environmental Stochasticity Fluctuations in reproduction and survival due to: Habitat alterations Increased interspecific pressure Competition Predation Parasitism Disease Natural disasters

6. Black stilts lay eggs in river bed gravels. Increasing frequency of flooding, due to rapid glacial melt, causes high egg mortality.

7. Environmental Stochasticity Fluctuations in reproduction and survival due to: Habitat alterations Increased interspecific pressure Competition Predation Disease Natural disasters

8. Competitive interactions between trout are influenced by water temperature. Come and get it! !#@?

9. Environmental Stochasticity Fluctuations in reproduction and survival due to: Habitat alterations Increased interspecific pressure Competition Predation Disease Natural disasters

10. Tropical frogs are highly vulnerable to chytridiomycosis. Chytrid fungus thrives within cloud forests. Climate change drives cloud formation at higher elevations.

11. Environmental Stochasticity Fluctuations in reproduction and survival due to: Habitat alterations Increased interspecific pressure Competition Predation Disease Natural disasters

13. How do you plan for these demographic and environmental uncertainties?

14. Population Viability Analysis (PVA) • A mathematical modeling procedure used to determine whether a population is likely to become extinct within a given time frame.

15. Population Growth Equation Nt+1 = Nt + B - D + I - E Where: B = birth rate D = death rate I = immigration rate E = emigration rate t = current time interval (e.g. this year) t+1 = next time interval (e.g. next year)

16. Population Viability Analysis Deterministic Models Variables Model Output Initial N = 500 Nt+1 = Nt + B - D + I - E Birth rate = 60 / yr Death rate = 60 / yr Probability of extinction within next 100 years: ~0% Immigration = 20 / yr Emigration = 20 / yr

17. Doctors say that Nordberg has a 50 - 50 chance of living. . . though there's only a 10 percent chance of that.

18. Population Viability Analysis Stochastic Models Probability Distribution Model Output Variables Initial N = 500 How often does the population survive: 10 yrs 50 yrs 100 yrs etc. . . Birth rate = ?

19. Probability Distributions 6 Number of possibilities 0 2 3 4 5 6 7 8 9 10 11 12 Combination

20. Probability Distributions- Deaths by age in the U.S. - % of deaths Age

21. Population Viability Analysis- deterministic vs. stochastic models - Stochastic Model Probability Distribution Model Output Variables (many repetitions) Initial N = 500 How often does the population survive: 10 yrs 50 yrs 100 yrs etc. . . Birth rate = ? Death rate = ? Fires, etc. = ?

22. PVA in action- the Northern Spotted Owl - Video A Video B

23. PVA in action- the Northern Spotted Owl - Population Size birth rate death rate emigration immigration barred owls West Nile V. logging fires nest predation

24. PVA in action- the Northern Spotted Owl - Suitable habitat (33 grey hexes) is randomly scattered.

25. PVA in action- the Northern Spotted Owl - Suitable habitat (33 grey hexes) is clustered in a single location.

26. PVA in action- the Northern Spotted Owl - Suitable habitat clusters surrounded by marginal habitat

27. www.vortex9.org/vortex.html

28. Minimum Viable Population (MVP) The smallest population size that can be predicted to have a very high chance of persisting for the foreseeable future.

29. PVA in Action- the Northern Spotted Owl - Suitable habitat (33 grey hexes) is randomly scattered.

30. PVA in Action- the Northern Spotted Owl - Suitable habitat clusters surrounded by marginal habitat

31. PVA & MVP can suggest how large populations should be.What if existing populations are too small?

32. Introductions / Reintroductions- Northern Rocky Mtn. Wolf - Flashdance is the greatest movie ever! (play video)

35. The Logistics of (Animal) Introductions/Reintroductions • Sufficient habitat • Sufficient food • Genetic diversity • Veterinary medicine • Social dynamics & learned behaviors • Long-term funding & political support

36. Wolves do kill. . .

38. . . . and cultural norms run deep

39. Ex-Situ Conservation- African Black Rhino - (click) (click)

40. Amphibians are dropping like flies (click)

41. Ex-Situ Conservation- The Amphibian Ark - ensuring the global survival of amphibians, focusing on those that cannot currently be safeguarded in nature

42. Ex-Situ Conservation- The Amphibian Ark - ensuring the global survival of amphibians, focusing on those that cannot currently be safeguarded in nature Amphibian Conservation Action Plan (www.amphibianark.org/pdf/ACAP.pdf)

43. Reading Assignments Read text p. 455-462.