1. Population Interactions

2.  Ecosystems are made of many populations living together  How do populations live together? ◦ 5 types community interactions  Competition  Mutualism  Commensalism  Parasitism  Predation

3.  Organisms compete for same resources (food, space, etc)  Nature doesn’t like competition ◦ Reduced through species occupy different NICHES – the physical and biological conditions  Include:  Food types  Predators  Temperature needed to survive

4.  An interaction in which organisms of both species benefits  +/+ relationship  In other words: Let’s work together!

5.  Example: Bees and flowering plants

6.  An interaction in which one organism benefits (the commensal) and the other organism has no benefit or harm (the host)  +/0 relationship  In other words: I don’t care what you do as long as it doesn’t affect me.

7.  Example: Clownfish and sea anemone

8.  An interaction in which one organism benefits (the parasite) and the other organism is harmed (the host)  +/- relationship  In other words: I’m stealing from you!

9.  Example: Ticks and Dogs

10.  Predation and parasitism are both +/- interactions, but there are several differences 1. The parasite is often much smaller than the host. 2. The parasite consumes only a small amount of the host at a time. Predators will eat most of their prey 3. Parasite can use host for other (protection, reproduction, etc). Predation only for food

11.  http://www.youtube.com/watch?v=63UAB4J2 r7Y http://www.youtube.com/watch?v=63UAB4J2 r7Y

12. Hookworms

13.  Strangler Fig

14. Zebra Mussel

15. Tongue Eating Louse