Predator-Prey Dynamics

Lectures 12-13

Functional response - definition

The uptake of resources/prey from the environment by a consumer/ predator as a function of the resource concentration

Resource - definition

A substance or an object that is required by an organism for normal maintenance, growth, and reproduction

When a resource is used, its amount is reduced

Consumer-resource interaction (types)

• Predation

• Herbivory

• Parasitism

• Cannibalism

Prey and predator equations

f=aNP=mortality due to predator=prey uptake by predators

Functional response- definition

The uptake by one predator

Functional response- equations

In this case, F is a linear function of prey density

Holling Type II properties

• F goes (0,0)

• F increases monotonically with increasing prey density

• Slope of F decreases with increasing prey density

• F converges asymptotically to a maximum uptake

Holling type II graph

Parameters:

U_max, k_s

Time spent handling/searching equations

Holling Type II Functional Response

Assumptions for Holling Type II

• Homogeneous Environment

• Random prey and predation distribution and movement

• Constant search rate

• Constant handling time

• No prey depletion

• No effect of hunger