Lecture 10 Flashcards
What are the two factors that determine if an interaction is a predator prey relationship?
If the predators reduce the prey population below K, and if the populations of predators and prey oscellate
What are the 7 assumptions of the lotka volterra predator prey model?
Predators exponentially decline with the absense of prey
prey exponentially increase with the absence of predators
all prey caught are converted into new predators
the attack rate is constant independent of the size of the prey population
There is no lag time, so an immediate response from the predator population
Predator attacks are random
There is a positive linear relationship between prey taken and predator numbers
What is the Lotka-Volterra Prey equation?
dH/dt = bH - aPh where dH/dt is the change in herbivore population size over time, b is per capita birth rate, H is the herbivore population size, a is the attack or kill rate of the predators in herbivores killed per predator per unit time per herbivore, and P is the number of predators
What is the lotka volterra predator equation?
dP/dt = eaPH - sP. where e is the efficiency with which dead prey are converted into predators, a is the attack rate, s is the per capita mortality rate of predators, P is the predator population size and H is the herbivore population size
What type of response is a linear relationship?
A Type 1 functional response
What is the equation dH/dt = bH - aPH?
The Lotka Volterra Prey equation
What is the equation dP/dt = eaPH - sP
The Lotka Volterra Predator equation
How do you find a zero net growth isocline?
Set the growth equation equal to zero and solve for the population size of the other population
How many functional response types are there?
three
What is a type one functional response?
Where the proportion of prey consumed by the predators is constant, there is no satiation. Used by the lotka volterra model, and shows a linear relationship
What is a type 2 functional response?
Where the number of prey consumed by the predators increases rapidly, but then decreases as the predators become satiated
What is a type 3 functional response?
Where prey consumption is low at low prey levels, then increases rapidly, before plateauing when the predators become satiated
What are six reasons for a type three functional response?
a heterogeneous environment could have limited refuges, so a higher proportion of the prey population is hidden at low prey densities
there is a lack of reinforcement of hunting strategies, it is inefficient
Predators might switch to a different prey source when prey is low, limiting the consumption of the prey population
At high prey populations, predators might congregate in areas with high prey densities
Predators might become satiated at a certain point, so their population plateaus
At high prey densities, handling time might start to cut into hunting time, so the hunting rate levels off
