Interactions within communities Flashcards
U5L4 (21 cards)
What are Communities?
A community refers to all of the populations within an ecosystem.
The growth rate of a population is often dependent on the growth rate of other population within the community.
What do organisms in an Ecological Niche include?
An organism in an Ecological Niche includes:
What/how it eats
How it reproduces
Tolerable Temp. Range
Habitat
Behavioral responses
What is a Fundamental Niche?
A fundamental Niche is an organism in ideal conditions (no competition or lack of resources).
It also makes optimal use of resources to maximize the health/growth rate of the population.
What is realized niche?
Realized niche is because of interspecific competition (between organisms).
Because of this competition, organisms most often occupy a portion of their fundamental niche.
What is interspecific competition?
It is when two species compete for a resource (aggressively), preventing the other from accessing a resource.
What is exploitative competition?
It is when two species share the same resource, lowering its availability.
What is Resource Partitioning
Resource partitioning aims to avoid/reduce competition over a resource.
Resources are divided by
organisms occupying two
nonoverlapping ecological
niches
(Anolis lizards).
What is predation?
Pred/Pray relationships are an interspecific interaction that affects the population of both pred/prey species.
These populations usually follow a pred/prey sinusoidal cycle. They are slightly offset though.
How does Pred-Prey cycling work?
The pred population is always lower than the prey population.
The predator population will lag behind the prey population slightly.
The populations will cycle at regular intervals.
What happens as Pred/Prey interact more?
Coevolution occurs. It is when the pred evolution directly affects the preys and vise-versa.
Preds will often evolve better senses and traits associated with hunting while prey will typically evolve better defense mechanisms.
What are Chemical defense mechanisms?
Prey develop a chemical means to make them poisonous/unpleasant to predators (like Skunks).
What are Morphological defense mechanisms?
Body structures which may be harmful to predators who chose to attack (porcupines).
What is camouflage?
The coloration of prey to avoid detection by blending with surroundings.
What is warning coloration?
Prey with chemical defenses may exhibit bright colouration to warn defenders.
What is Mimicry?
Mimicry is coloration designed to mimic the warning coloration of another species.
Difference between Batesian and Mullerian Mimicry?
Batesian: Harmless species mimic harmful species to benefit from defense mechanisms
Mullerian: Several harmful species all share similar warning patterns to reduce predation.
What is Symbiosis?
Symbiosis means ‘living together’.
Two difference species live in close, physical contact.
What are the three types of Symbiotic relationships?
Mutualism
Commensalism
Parasitism.
What is Mutualism?
Both organisms benefit.
Obligatory mutualism is when both animals require one another to survive.
Ex: Bees carrying pollen for flowering plants.
What is Commensalism?
Commensalism is when one organism benefits while the other remains unaffected.
Ex: Spiders building webs in the trees.
What is Parasitism?
Parasitism is when one animal benefits and the other is harmed.
Ex: Ticks attach to dead for days.
