Competition For Resources (C5) Flashcards
IFD =…?
Competition through the exploitation of a common resource.
IDD = …?
Resource defense competition.
Flow of concepts throughout Behavioural Ecology? (3)
Individual + Food
|
Individual + Food + Predation
|
Individual + Food + Intraspecific competition
How does the presence of conspecifics influence the individual’s behaviour?
How does competition influence population dynamics?
• Influences reproductive success & survivability.
• Provide more info, pls.
How does competition influence the distribution of the individuals?
Increased competition causes the outcompeted individuals to move to poor areas even though they have less resources.
Essential resources that lead to intraspecific competition? (3)
• Food.
• Territory.
• Mates.
Competition for resources leads to changes in? (3)
• Behaviour.
• Morphology.
• Physiology.
All changes in behaviour, morphology & physiology drive/lead to…?
Evolution.
IFD assumptions besides “ideal” & “free”? (3)
• No territoriality.
• No fighting.
• Prey items consumed by one individual become unavailable to others.
Optimal behaviour/ IFD equation?
U = Q/n
IFD equation symbols? (3)
U = value of the environment.
Q = quality of the environment.
n = number of individuals.
U = Q/n?
Population is partitioned between the environment in proportion to the environment’s relative productivity.
Why the “Ideal” in IFD?
Assumes that individuals are ideal as they have complete information about the availability & distribution of resources.
Why the “Free” in IFD?
Assumes that individuals are free to move from one area to another.
Explain IFD graph? (2)
● Because you have an equal reward in both habitats, you are free to go into any habitat, rich or poor (individuals who go into the poor habitat still gets the exact amount of resources).
● As you have more individuals coming into an area, more individuals will share resources, resulting in a less reward per individual.
IFD prediction?
Competitors adjust their distribution so that all individuals have the same rate of resource acquisition (i.e., high quality areas will have the most individuals & low quality areas will have the fewest individuals).
IDD attribute?
• The stronger competitors secure the better habitat.
Why the “Ideal” in IFD?
Assumes that individuals have complete information about resource availability.
IFD axes? (2)
• x-axis = number of competitors.
• y-axis = reward per individual.
Explain IDD graph? (3)
● Rich environment is over poor habitat.
● a = rich habitat becomes full & newcomers are forced to occupy poor habitats.
● When b is reached, further competitors are excluded from resources.
IDD axes? (2)
• x-axis = number of competitors (a & b).
• y-axis = number of individuals gaining resources.
Egs of IDD? (2)
• Parsus major: woodland vs hedgerow.
• Red grouse.
Explain Parsus major? (3)
● Oak woodland is the best breeding habitat but is quickly occupied & becomes completely filled with territories.
● Filled Oak woodlands force excluded individuals to occupy hedgerows where there is less food & ultimately less breeding success.
● If birds are removed from the best habitat then the ones occupying the hedgerows move to the woodlands.
Expkain Red grouse?
Territorial birds defend the richest areas as breeding & feeding territories, resulting in excluded birds exploiting poor areas with low survival rate.
Harper 1982 paper summary? (3)
● An eg of IFD with unequal competitors.
● Population showed a distribution of ducks according to the IFD but some ducks were better competitors than others & grabbed most of the food.
● Therefore, there was unequal distribution of resources.
Habitat selection in stem mother aphids? (3)
● An eg of both IFD & IDD models.
● It first appears that females follow the IFD as there are more of them in large leaves & less of them in small leaves, and would each get an equal amount of juice but…
● We observe later on that females follow the IDD as well due to females located at the base of the leaf getting more juice than those located away from the base of the leaf.
IFD stands for?
Ideal Free Distribution.