2. Why are species going extinct?
Fig
55.6

3. Nearly Extinct Species: maybe only 100 individuals exist

4. Extinction Vortex

5. Attwater Prairie Chicken
As population declined, genetic diversity declined
Similar to
Fig 55.12

6. Attwater Prairie Chicken
Individuals brought from other populations increased reproduction and population
Similar to
Fig 55.12

7. Yellowstone NP 63 mi 54 mi 466 mi of roads
950 mi of backcountry trails
97 trailheads
287 backcountry campsites

9. Wolves in Yellowstone National Park

10. The last wolves in Yellowstone (1920’s)

11. Wolves commonly live in packs

12. Packs can kill larger prey
Social vs
Solo

13. Packs give the ability to obtain more food, but also mean sharing food, reduced chance of reproduction, and increased chance of diseases.

14. Wolves are very territorial and will kill intruders

15. Wolves were re-introduced to Yellowstone in 1995

16. Wolf relocation

17. “hard” release:
directly to new location
In Yellowstone used“soft” release:
Kept in 1 acre pens to acclimate to new environment

18. Wolves were re-introduced to Yellowstone in 1995

19. Yellowstone area wolf packs 2004

20. Wolf deaths
38 deaths= 33%

21. The cost of wolves in Yellowstone NP:
Currently about 300 wolves
2003-
137 sheep and 66 cattle = $32,000
2004-
209 sheep, 57 cattle, and 6 other animals = $70,000

22. Estimate millions of dollars in increased visitors

23. Predator-predator interactions

24. Predator-predator interactions

25. Yellowstone Grizzly Bear population increases

26. Wolves are decreasing the elk population

27. Benefits of decreasing herbivore populations

28. Increased Riparian Habitat

29. Increased Riparian Habitat
Fig 2

30. Increased Riparian Habitat
Fig 2

31. Increased Riparian Habitat
Fig 3

32. Are wolves responsible?
year
Fig 5

33. high risk
low risk

34. Are wolves responsible?
year
Fig 5

35. Protection vs herbivory
gully depth vs browsing
Fig 6

36. The greatest difference has been in the deepest gullies, which are at the greatest risk of erosion.
Fig 6

37. The reintroduction of wolves to Yellowstone NP has had numerous positive benefits.

38. The reintroduction of wolves to Yellowstone NP has had numerous positive benefits: More food available for other carnivores

39. The reintroduction of wolves to Yellowstone NP has had numerous positive benefits: Increased Riparian Habitat
Fig 3

40. Animal behavior is unpredictable and inexplicable
Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 231