Predation

True predator, grazer, parasite, parasitoid

True predator, grazer, parasite, parasitoid

types of predators

interactive predator-prey relationship

Might expect oscillations in pred & prey over time
• Predators lag behind prey

prey switching

when one prey gets rare, the predator eats something else

territoriality

predators limit themselves from becoming too numerous in an area

non interactive, predator can’t eat all prey, low predator efficiency

What conditions allow for coexistence of predator and prey

type 1

predator functional response with constant catching efficiency

Holling

Ecologist who developed model of functional responses for predator and prey density

type 2

predator functional response with predator satiation at high prey densities→ cannot control prey anymore

type 3

functional response that keeps predator satiation but also adds prey switching due to optimal foraging theory

no

Are specialist predators likely to be type 3?

prey density and percent taken

What is on the axis of a functional response graph?

lower

N.S. favors traits in prey that __________ predation efficiency

long legs, parental care, camouflage, warning coloration, large groups

what are examples of traits that evolve in prey due to predation?

coloration, better catching mechanisms, aggressive mimicry

what are examples of traits that evolve in predators due to predation?

no

do predators voluntarily reduce their predation pressure at low prey densities?

evolutionary arms race

what is the evolution of predator and prey in relation to each other an example of?

prey, if they lose they are dead

who wins the evolutionary arms race? why?

logistic

model used in hollings’s predation predictions

carrying capacity

Highest N that is sustainable by the resources

where kill and birth lines intercept

where is the equilibrium point on a predator/prey graph

away from

in a type 2 model, is the population driven towards or away from the equilibrium point

towards

in a type 1 model, is the population driven towards or away from the equilibrium point

in the middle, not at high or low abundnace

where is a type 3 predator efficient

predator and prey are interactive

assumption of Rosenzweig-MacArthur Model

equilibrium point where things should stay constant

what is an isocline on a graph?

B

At which points is prey lamda greater than 1

predator zero isocline

line where predator population growth is zero and predator lamda is equal to 1

not enough territory

why does predator population decrease even when there is enough prey

oscillates so one shrinks than the other and then repeats

pattern of interactive single predator and single prey population over time

environmental shift

what can shift the equilibrium of a predator/prey interaction

A

which habitat is more productive A or B