1. Social Interactions

2. Interspecific Competition
Competition for shared or scarce resources
Often food or space
When this occurs, one of the competing species must:
Migrate
Adapt (shift feeding habits or behavior)
Become extinct
Evolve

3. Resource Partitioning
Species competing for similar scarce resources evolve more specialized traits that allow them to use shared resources at different times, in different ways, or in different places
Species 1
Species 2
Region of
niche overlap
Resource use
Species 1
Species 2

4. B. Mutualism – two organisms live together, both benefit Examples: Anemone & clownfish Hippopotamus & bird Termite & amoeba that live in the intestines Cleaner fish and shrimp

5. Examples of mutualism in action
-One version of symbiosis is the relationship of certain birds and hippopotami.
-In this relationship, the birds are well known for preying on parasites that feed on each hippopotamus which are potentially harmful for the animal.
-To that end, this hippopotamus openly invites the birds to hunt on its body, even going so far as to open its jaws to allow the birds to enter the mouth safely to hunt.
-For the birds' part, this relationship not only is a ready source of food, but a safe one considering that few predators would dare strike at the bird at such close proximity to its host.-

6. Acacia Trees and Ants

8. A. Commensalism – two organisms live together one benefits one is unaffected Examples: Trees & orchids Monarch butterfly & milkweed Whale & barnacle

9. Example of Commensalism in Action: Shark & Remora
Remora sharks are endowed with an adhesive disk on the dorsal surface of their heads. 
 They use this adhesive disk to “hitch a ride” on larger animals, usually whales, which tend to be sloppy eaters.  
When food floats away from the whale’s mouth, the remora can unhitch itself and collect the scraps of food floating by. 

10. Parasitism – two organisms live together one benefits one is harmed Examples: Tapeworm & human Fleas & dogs

11. Parasitism in Action – Ticks and Dogs
Ticks harm their hosts, such as dogs, by biting their skin, sucking their blood, and causing them to itch. The ticks, in turn, get food and a warm home.

12. Lamprey & Carp

13. Ecological Succession: communities in transition
Gradual change in species composition of a given area over an extended period of time
2 types
Primary
secondary

14. Ecological Succession
Primary Succession
Begins after a disturbance to the ecosystem (ie glacier retreating, volcanic eruption, parking lot)
Begins with bare rock and must form soil before plants can begin to grow
Pioneer species (lichens and mosses) attach themselves to the bare rock and break it down to form soil

16. Ecological Succession
Secondary Succession
Occurs when area has been disturbed, but some soil remains
Abandoned farms, burned or cut forests, flooded land
Faster than primary succession