1. Predator Prey Relationships

2. SpecialistSpecialist –Relies on something specific –Out competes generalist GeneralistGeneralist –Doesn’t rely on anything specific –Out adapts specialist Direct/specialist relationship

3. Food webs are sometimes simplified (conceptually) to the drama of a single predator-prey interaction but, these are the (proverbial) tip of the iceberg. Ecological community interactions are extremely complex…

5. Food web interactions can be: Direct and/or indirect. Acute and/or chronic. Spatially distinct and/or diffuse. Multigenerational and/or unique to a particular moment in time

6. How are communities regulated?

7. Keystone Species: Species that an entire ecosystem’s health depends on

8. Top-down regulation ( trophic cascade) : keystone species are predators Regulation of community structure…

9. Pisaster (starfish): Keystone Predator?

10. Robert Paine (1969)

11. Effects of removing a Keystone species

12. Wolves as a Keystone Predator Yellowstone wolves control elk populations in two important ways: 1)Elk population numbers are reduced 2)Modify elk behavior

13. http://www.pbs.org/wgbh/nova/wolves/lonesome.html The Ecology of Fear http://www.pbs.org/wnet/nature/episodes/in-the-valley-of-the-wolves/video-wolves-on-the-hunt/220/

15. Bottom-up regulation … Primary producers drive community structure? Regulation of community structure…

16. Bottom-up regulation… Primary producers drive community structure? Regulation of community structure…

17. Keystone Herbivory Regulation of community structure…

18. Madagascar Flying Fox: A Keystone Seed Disperser? Regulation of community structure…

19. Beaver- A keystone landscape engineer

20. Other Keystone Species

21. The End