topic 3: other relationships with ecosystems predator-prey relationships predation: a predator eats...
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Topic 3: Other Relationships with Ecosystems
Predator-Prey Relationships
Predation: a predator eats a prey.
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 RelationshipPredation: 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.
Boom and Bust, Predator and Prey
Predation Avoidance
Predator/prey Predator/prey relationships are relationships are complexcomplex
Prey have various Prey have various defense defense mechanisms:mechanisms: CamouflageCamouflage MimicryMimicry
1. Camouflage1. Camouflage
Adaptation in Adaptation in form, shape or form, shape or behaviorbehavior Snowshoe hare Snowshoe hare
White in winterWhite in winter FrogsFrogs
Dark on topDark on top Light Light
underneathunderneath
Camouflage Hides Prey
When organism takes on coloring, shape, or When organism takes on coloring, shape, or behaviour that will provide it with an advantagebehaviour 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.
Mimicry ..only one dangerous!!
Viceroy Butterfly
Monarch Butterfly
Competition: an interaction in which two or more organisms battle for the same
resources.
CompetitionInter-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
Barnacle Competition
Intraspecific competition
Interspecific competition
Gause’s Principle
No 2 species can occupy
same ecological niche
Ultimatein inter-specific
competition
Species 1
Species 2
Competition leads to exclusion
Paramecium
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.
Symbiosis
Symbiosis: two or more species live in close contact
Three types: Mutualism Commensalism Parasitism
Mutualism: a symbiotic relationship in which both species benefit (+/+)
Bali Island, Indonesia. A cleaner shrimp
cleaning parasites from a moray eel's mouth
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).
Commensalism: a symbiotic relationship in which one organism benefits, and the other organism is neither helped nor harmed. (+/0)
CommensalismCommensalismOrchid on tree
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
ParasitismParasitism
Lymphatic Lymphatic FilariasisFilariasis (Elephantiasis) (Elephantiasis)
The disease is caused The disease is caused by by parasitic wormsparasitic worms, , including including Wuchereria Wuchereria bancroftibancrofti, , Brugia Brugia malayimalayi, and , and B. timoriB. timori, , all transmitted by all transmitted by mosquitoes. mosquitoes.
Bed Bugs - They do exist!