Interspecific Competition Flashcards
(19 cards)
What is interspecific competition?
Competition amongst individuals from more than one population/species
What is +-predation?
Where one animal benefits and the other one doesn’t benefit
What is +0 commensalism?
One species benefits and the other has no effect
What is -0 ammensalism?
Where one species has an adverse effect on another, but to no advantage to itself
What is ++mutualism?
Both species benefit
What is - - interspecific competition?
Both species suffer
What does competition cause a decline in for both species?
Decline in fecundity, survival or growth
What is it called when one population becomes extinct due to interspecific competition?
Competitive exclusion
Give an example of competitive exclusion:
Flour beetles (tribolium)
T. castaneum out competed T. confusum in hot moist environment
T. confusum better adapted to cold moist or hot dry environment
T.confusum has a competitive advantage when parasites present, this is reversed when parasites are removed
Describe Tansley’s Galium study:
Carried out on G.saxatile and G.sylvestre
Both can grow on limestone and peat when grown alone
G.sylvestre better on limestone
G.saxatile better on acid soil
What is a niche of an organism?
The set of environmental conditions that an organism likes and needs to survive
What can the niche of an organism be called when you consider a number of variables?
The n-dimensional hypervolume
What is the fundamental niche?
The one in which a species can live in the absence of all competitors, it is a larger niche than its usual one
What is the actual niche of an organism called?
The realised niche
What two things can an animal do in order to partition the niches?
- Change the components of their niches e.g use a different tree
- Change themselves morphologically= “character displacement”
What effects can resource partitioning have?
Reduces amount of interspecific competition
Increases amount of intraspecific competition
Niche requirements are now narrower
Give an example of character displacement
Mud snails (Hydrobia ventrosa and H. ulvae) Both species feed on algae found on detritus on the mud
When found alone they’re both 3.5mm
When together H. ulvae became larger (4mm) and H. ventrosa smaller (<3mm)
The size of the food particles they eat is directly proportional to body size
Describe the character displacement in Darwin’s finches
In the Geospiza species
When G. fortis and G. fuliginosa both live together on Santa Cruz G. fulignosa has a smaller beak so there’s no overlap
What are guilds?
A group of species exploiting the same resource in a similar way
