1. Putting Animal Physiology and Ecology together… Grizzly Bears

2. Ecological Interconnections

3. We are only one of millions of species on earth.

4. Why are species going extinct? Fig 55.6

5. EXTINCT FEWER THAN 100 REMAIN For some species it is already too late...

6. Habitat loss and fragmentation has been extensive in the US due to human modification of the environment

7. Grizzly Bears

8. Grizzly bears are big.

9. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 28 How are bears related to each other?

10. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 15 12,000 years ago: the grizzly ancestor short- faced bear

11. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 17 and 23 Short-faced vs grizzly bears

12. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 28 How closely related are these bear species?

13. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 200 Grizzly-Polar bear hybrid (from a zoo)

14. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 78 Grizzly bears live most of their lives alone

15. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 78 Grizzly bears live most of their lives alone. What do they do?

16. The Digestive System Fig 43.5

17. Different mouth and teeth structures can tell about an animal’s diet

19. Grizzly bear teeth

20. Carnivores have a short digestive system Herbivores have a long digestive system

21. HumansBears Both humans and grizzly bears are omnivores. Our digestive systems can tell us about our ancestors.

22. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 54 cat dog grizzly panda Different teeth and diets

23. About 75% of their diet is plants

24. They also eat carrion.

25. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 85 Some grizzlies are excellent predators, but most eat carrion.

26. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 186 Grizzlies constant search for food can lead to conflicts with humans.

27. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 215 Grizzlies constant search for food can lead to conflicts with humans.

28. There is not much to eat in winter...

29. Bears from temperate climates sleep over the winter in a den. (not hibernation)

30. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 62 and 63 Grizzlies have an amazing ability to gain and lose weight.

31. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 59 Grizzly reproduction

32. winter fall summer spring young born den w/ mother juveniles on own Female Grizzly Bear reproductive cycle Females are not fertile when caring for offspring fertiliz- ation

33. SpringSummerFall Winter (in den) Birth year copulation delayed implantation gestationbirth Juvenile year 1 Offspring with mom (lactation) Offspring with mom (lactation) Offspring with mom (lactation) Offspring den with mom (lactation) Juvenile year 2 Offspring with mom (lactation) Offspring with mom (lactation) Offspring with mom (lactation) Offspring den with mom (lactation) Adolescent year Offspring with mom (lactation) Offspring on own Grizzly Bear Reproduction

34. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 58 Grizzly cubs are born in the den and are very small (~1 lb)

35. winter fall summer spring young born den w/ mother juveniles on own Female Grizzly Bear reproductive cycle Females are not fertile when caring for offspring fertiliz- ation

36. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 76 Female bears are very protective of their young

37. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 77 Infanticide: males will try to kill young so that mother will become fertile

38. Human-Bear Interactions

39. Historical Grizzly Bear range Current Grizzly Bear range

40. Hunting Grizzlies

41. Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 216 Hunters

42. Studying Grizzlies CB 55.11

43. 63 mi 54 mi 466 mi of roads 950 mi of backcountry trails 97 trailheads 287 backcountry campsites Yellowstone NP

44. Yellowstone Grizzly Bear population increases

45. Where do grizzly bears fit? Are they important? How much of our resources should we share with grizzly bears?

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

47. Next: Ecology...