Lecture 26 & 27: interspecific competition Flashcards
Competition
Use or defense of a limiting resource by an
individual reduces its availability to other
individual
Competitive Displacement/Competitive Exclusion Principle
Competitive Exclusion Principle
“Gause’s Law”
Georgy Gause
two species can not coexist indefinitely when both are
limited by the same resource
“complete competitors cannot coexist”
-one species is better at obtaining the resource
-one species is better able to survive when the
resource is scarce
Lotka-Volterra competition models
competition between 2 species for a single resource
Lotka-Volterra competition models: equilibrium population sizes of 2 species
Lotka-Volterra competition models: species 1 excludes species 2
Lotka-Volterra competition models: species 2 excludes species 1
Lotka-Volterra competition models: winner depends on initial conditions
Lotka-Volterra competition models: coexistence
coexistence is most likely when
interspecific competition is weaker
than intraspecific competition
i.e., when 𝛼 and 𝛽 are less than 1
Exploitation VS. Inferterence Competition
Interference: Competitors will physically fight to get all the food for themselves
Exploitation: Competitors will quickly take as much resource as they want, they don’t fight others.
Exploitation VS. Inferterence VS. Apparent
Appartent: Their “competition” can be how they share the same predator
Interference: Competitors will physically fight to get all the food for themselves
Exploitation: Competitors will quickly take as much resource as they want, they don’t fight others.
Interference competition ex
Competitors will physically fight to get all the food for themselves
Both diff species of ants compete for the same grain so ant species 1 will plug the species 2 ant hill entrance so they cant get out in the morning and forage for grain which allows species 1 to collect more grain.
Nothing physical happens, they just play tricks to “slow” or inconvenience species so they theyselves can get an advantage
