Competition, Predation, and Symbiosis

1. Competition, Predation, and Symbiosis Interactions within a community

2. Niche (nitch or neesh) • The role of an organism in its habitat • each species is specially adapted to its niche • Includes: • Type of food it eats • How it gets its food • What eats it (predators) • Conditions it requires to survive and reproduce

3. Adaptations • Organisms are adapted to survive in their niche • Adaptations: Behaviors or physical traits that allow organisms to live successfully in their environments

5. Natural Selection: How a trait that makes an individual better suited to its environment may become common in the species Survival of the fittest Individuals who are best suited to their environment are more likely to survive and reproduce and pass their traits on This makes their unique traits more common in the species Results in adaptations How do organisms become adapted to their niche? Natural Selection

6. An organism does NOT change its traits to suit the environment Adaptations that can be changed through natural selection are GENETIC Remember…

7. Competition • The struggle between organisms to survive as they try to use the same resources • If organisms try to occupy the same niche, they are competing. • One will either die out or move • Organisms avoid competition by occupying slightly different niches

8. Examples: • Lions and Hyenas compete for the same food • Kudzo, and invasive plant in the south, crowds out the native plants in a competition for space

9. Predation • When one organism kills another for food • Predator: The hunter • Prey: The hunted • Both are adapted to help them survive

10. Predator Prey Interactions • Predators depend on prey to survive • When the population of prey is low, the population of predators will go down • When the prey population goes up, predator populations tend to go up as well • It is a cycle

11. Symbiosis • a close relationship between two species, where at least one of the species benefits • Three types: Mutualism, commensalism, parasitism

12. Mutualism • We’re friends! • Both organisms benefit from the relationship

13. Commensalism • We are sort of friends…Sometimes you open my locker for me when it’s stuck because you are stronger then me… • One organism benefits, and the other is neither helped or harmed

14. parasitism • We are NOT friends. We are enemies. • One organism lives on or in another organism and causes harm • Sometime a parasite lives on its host permanently (tapeworms), sometimes it is temporary (mosquitoes)

15. Common parasites

16. Brown headed cowbird: lays its eggs in other birds nest to be raised by other birds at the expense of their own young. Other types of parasites

17. Galls: Growths on plants caused by insects, fungi, bacteria, viruses. Very common.

18. Isle Royale is an island in Lake Superior There is a population of moose and wolves that lives there. The relationship between the moose and wolves has been studied since 1958. This is the longest predator prey study ever done. Moose and Wolves of Isle Royale • There are no permanent populations of people living on Isle Royale • It is a national Park (hunting is illegal)

19. The Moose • The first moose arrived around 1900 by probably swimming the 15 miles from Canada • Wolves are its only predator • Moose need to eat about 40 lbs of food/day to survive • Ticks, food supply, and weather all affect the survival of moose (limiting factors)

20. The Wolf • They arrived on Isle Royale around 1950 by using an ice bridge from Canada (probably) • Moose are its main food source (90%). They will also eat snowshoe hare and beavers • Beside starvation, they die due to fights with other wolves over food (competition)

21. The Study

22. Other parts of the Isle Royale Community • Balsam Fir • Ravens • Red Fox • Red Squirrels • Moose ticks • Beaver • Snowshoe hare