2. An interaction in which one animal (the predator) captures and feeds on another animal (the prey) is called predation.

3. Predators can affect the size of prey populations in a community and determine the places prey can live and feed. Idealized computer model

4. This graph shows the fluctuations in wolf and moose populations on Isle Royale over the years.

5. An interaction in which one animal (the herbivore) feeds on producers (such as plants) is called herbivory.

6. Herbivores, like a ring- tailed lemur, can affect both the size and distribution of plant populations in a community and determine the places that certain plants can survive and grow.

7. In some situations, human activity limits populations. Fishing fleets have raised cod death rates so high that birthrates cannot keep up. As a result, cod populations have been dropping.

8. Acute Smell Acute Eye Sight Acute Hearing Venom Secrete webs Sharp teeth Camouflage

9. False Coloration: moths using false eye spots to scare away predators Mimicry: one species closely resembles another species. King Snake mimics Coral Snake, Viceroy Butterfly mimics the Monarch. Unpleasant Scents: Skunks Protective Covering: turtles, porcupine, armadillo, sea urchins Camouflage: blending in to the environment. Green leaf mantid, walking stick insect Warning Colors: instead of hiding they adopt bright colors to warn predators they are toxic or dangerous. Poison Dart frog

10. When populations become crowded, individuals compete for food, water, space, sunlight, and other essentials. Competition is a density- dependent limiting factor. The more individuals living in an area, the sooner they use up the available resources.

11. Interspecific Competition Competition between members of different species. Intraspecific Competition Competition between members of the same species.

12. Direct competition between different species almost always produces a winner and a loser—and the losing species dies out. Dotted line – grown separately Solid line – grown together

13. The competitive exclusion principle states that no two species can occupy exactly the same niche in exactly the same habitat at exactly the same time.

14. Instead of competing for similar resources, species usually divide them. The resources utilized by these species are similar yet different. Therefore, each species has its own niche and competition is minimized.

15. The close and often long- term interactions between biological species. Parasitism Mutualism Commensalism

16. Relationships in which one organism lives inside or on another organism and harms it. Generally, parasites weaken but do not kill their host, which is usually larger than the parasite. Parasitism

17. Also known as cooperation. Both organisms gain a fitness benefit. Ex, clown fish and anemone

18. A relationship in which one organism benefits and the other is neither helped nor harmed. Ex, barnacles on whale

19. Ecosystems change over time, especially after disturbances, as some species die out and new species move in. Ecological succession is a series of more-or-less predictable changes that occur in a community over time.

20. Volcanic explosions can create new land or sterilize existing areas. Retreating glaciers can have the same effect, leaving only exposed bare rock behind them.

21. Succession that begins in an area with no remnants of an older community is called primary succession.

22. The first species to colonize barren areas are called pioneer species. One ecological pioneer that grows on bare rock is lichen—a mutualistic symbiosis between a fungus and an alga.

23. Sometimes, existing communities are not completely destroyed by disturbances. In these situations, secondary succession occurs. Secondary succession proceeds faster than primary succession, in part because soil survives the disturbance. As a result, new and surviving vegetation can regrow rapidly.