2. Topic 3: Other Relationships with Ecosystems

3. Predator-Prey Relationships Predation: a predator eats a prey.

4. Predator-Prey relationships are cyclical. When the prey’s population rises, there is more food for the predator so immediately their population goes up. Predation: A Cyclical Relationship What is happening in this graph? When there is too many predators eating the prey, the population of prey drops… now there isn’t enough food for the predators so their population drops… and so on.

5. Boom and Bust, Predator and Prey

6. Predation Avoidance Predator/prey relationships are complex Predator/prey relationships are complex Prey have various defense mechanisms: Prey have various defense mechanisms: Camouflage Camouflage Mimicry Mimicry

7. 1. Camouflage Adaptation in form, shape or behavior Snowshoe hare Snowshoe hare White in winter White in winter Frogs Frogs Dark on top Dark on top Light underneath Light underneath

8. Camouflage Hides Prey

12. When organism takes on coloring, shape, or behaviour that will provide it with an advantage When organism takes on coloring, shape, or behaviour that will provide it with an advantage 2. Mimicry Dronefly, a bee mimic, on Dandelion flower – note that the shape of the eyes, the number of wings (2 as opposed to 4) and a wide waist distinguishes it from the honeybee; but from a distance one is easily fooled.

13. Mimicry.. only one dangerous!!

14. Viceroy Butterfly Monarch Butterfly

15. Competition: an interaction in which two or more organisms battle for the same resources.

16. Competition Inter-specific Competition: between 2 members of different species Intra-specific competition: between 2 members of same species Competition can be for food, space, mates, oxygen, water

17. Barnacle Competition Intraspecific competition Interspecific competition

18. Gause’s Principle No 2 species can occupy same ecological niche Ultimate in inter-specific competition Species 1 Species 2 Competition leads to exclusion Paramecium

19. The competitive exclusion principle (aka Gause’s Law) States that two species that compete for the exact same resources cannot stably coexist. One of the two competitors will always have an ever so slight advantage over the other that leads to extinction of the second competitor in the long run.

20. Symbiosis Symbiosis: two or more species live in close contact Three types: Mutualism Commensalism Parasitism

21. Mutualism: a symbiotic relationship in which both species benefit (+/+) Bali Island, Indonesia. A cleaner shrimp cleaning parasites from a moray eel's mouth

22. An example of mutual symbiosis is the relationship between clownfish that dwell among the tentacles of tropical sea anemones. The territorial fish protects the anemone from anemone-eating fish, and in turn the stinging tentacles of the anemone protect the clownfish from its predators (a special mucus on the clownfish protects it from the stinging tentacles).

23. Commensalism: a symbiotic relationship in which one organism benefits, and the other organism is neither helped nor harmed. (+/0)

24. Commensalism Orchid on tree

25. Parasitism: a symbiotic relationship in which on one organisms benefits, while the other is harmed. (+/-) Tapeworm: Humans occasionally become infected by ingesting cereals contaminated with insect pests (intermediate hosts of this parasite). Symptoms include abdominal pain, diarrhea and headache. Intestinal Roundworm

26. Parasitism

27. Lymphatic Filariasis (Elephantiasis) Lymphatic Filariasis (Elephantiasis) The disease is caused by parasitic worms, including Wuchereria bancrofti, Brugia malayi, and B. timori, all transmitted by mosquitoes. The disease is caused by parasitic worms, including Wuchereria bancrofti, Brugia malayi, and B. timori, all transmitted by mosquitoes.

29. Bed Bugs - They do exist!