Ecology Notes – Part 3: Interactions Biology Spring 2012 Biology Spring 2012

Interactions Types of Interactions among organisms Symbiosis (3 types) Competition Predator/Prey (Predation)

Interactions – Symbiosis Symbiosis: the relationship between two organisms in which at least one benefits, but the other does not die Sym – = with / together -biosis = mode of life Ex: bird on hippos, fleas on dogs

Symbiosis 3 Types of Symbiosis: Commensalism Mutualism Parasitism

Symbiosis Commensalism: one organism benefits and the other is not harmed (+/0) Ex: Lichen on a tree branch Maggots decomposing a rotting carcass

Symbiosis Mutualism: both organisms benefit from the relationship (+/+) Ex: Clown fish and sea anemone Insect pollination of flowers

Symbiosis Parasitism: One organism benefits and the other is harmed, but not killed (+/-) Ex: mosquito and human

Interactions – Competition Competition: When different species struggle over the same resource Resources are limited by supply Water, food, shelter

Interactions – Competition Revisiting the niche… Niche: the role of an organism in its environment, “how it makes a living” How it gets food Habitat conditions for survival Is it used for food? All its biotic and abiotic resources

Interactions – Competition Niche Example

Competition, cont. Competition can happen in two ways: Between two different species (interspecies) Cheetahs & lions competing for antelopes. Between members of the same species (intraspecies). Mountain goat rams butting heads to “win” the females.

Interactions – Competition Competitive Exclusion Principle: If two species compete for the same resource(s), one will win and one will lose The “winner” gets the territory / resource(s) The “loser” will either move to another location or get killed

Why are they in different regions of the tree??

Interactions – Predator/Prey

Predation: where one organism kills another for its food Organism getting the food is the predator Organism that is the food is the prey 1 lives & 1 dies

Which is which? /ns/technology_and_science- science/t/gator-guzzling-python- comes-messy-end/

To succeed... Both predators and prey adapt to better survive Predators get better at catching prey Prey get better at avoiding being caught.

What do they need? Think of a predator/prey relationship Generate a list of characteristics that are helpful for each to survive… Predators: Prey:

Predator adaptations Speed & agility or power & strength Acute senses “Weaponry:” claws, fangs, poison Camouflage

Prey Adaptations Avoid: Speed, senses, hide, mimic

Prey Adaptations Warn: Coloring, smell, cry

Prey Adaptations Defend: Shell, needle, fight back, taste, smell...

Interactions – Overview Write a general description of what happens to each organism in the following types of interactions among organisms: Symbiosis: Describe each of the 3 types of symbiosis Competition: Predator/Prey (Predation):

Interactions – Overview Types of Interaction One organismThe other organism… SymbiosisDoesn’t die Competition Predator / Prey

Predator-Prey Simulation “Queen of Trees” Interactions