Modelling Predation

Question 1

What is Constitutive Defences?

Answer 1

Structure on its body are always present

Question 2

What is Induced Defences?

Answer 2

Only develops when it detects a threat

Question 3

What are the Structural Defences of Plants?

Answer 3

Thorns, Spines and Trichomes

Question 4

Thorns

Answer 4

modified branches

Question 5

Spines

Answer 5

modified leaves

Question 6

Trichomes

Answer 6

• little hairs that grow on a plant
  
  • deter small herbivores
  • depending upon stiffness, large herbivores

Question 7

Chemical Defence: Aposematism

Answer 7

warning colouration to warm off a predator

Question 8

Chemical Defence: Batesian Mimicry

Answer 8

• organisms evolve similar markings to Unrelated unpalatable/poisonous species

Question 9

Chemical Defence: Mullerian Mimicry

Answer 9

• co-occurring species evolve similar warning colours
• All unpalatable/poisonous

Question 10

What are the consequences to reduced activity in the presence of predators?

Answer 10

low food = can’t produce much colour red to warn off predators
High food = produces red (bright) so it warns off predators

Question 11

Co-evolutionary Arms Race

Answer 11

constant evolution of new defences by prey = ability to overcome defences by predators

Question 12

Do predators also evolve?

Answer 12

when a prey evolve to less predation but predator would evolve again by overcoming that evolution produced by the prey and this goes in circle

Question 13

Learned Delayed Density Dependence causes population cycling to

Answer 13

• overshoot carrying capacity
• Delayed response to changing resource availability

Question 14

Prey Population (N): (dN/dt) = rN - cNP

Answer 14

• (dN/dt) : change in prey population
• rN: growth of prey pop’n
• c: capture efficiency
• NP: encounter rate b/w predator and prey

Question 15

Predator Population (P): (dP/dt) = acNP - mP

Answer 15

• (dP/dt): change in predator population
• a: efficiency of converting food/prey into offspring
• cNP: # of prey consumed
• mP: mortality rate of predators

Question 16

Prey Population will be stable when rN - cNP =

Answer 16

0 (zero)

Question 17

Stability occurs when growth rate =

Answer 17

predation rate

Question 18

P = r/c represents

Answer 18

number of predators = prey growth/ predator capture efficiency

Question 19

P < r/c means Prey population

Answer 19

increases

Question 20

P>r/c means Prey population

Answer 20

decreases

Question 21

Predators population: N = m/ac represents

Answer 21

• number of prey

Question 22

N = m/ac would only represents stability when

Answer 22

when prey is sufficient to support predator mortality / addition of new predators

Question 23

N > m/ac means Predators population

Answer 23

increases

Question 24

N < m/ac means predators population

Answer 24

decreases

Question 25

graph in Horizontal direction: Top box is

Answer 25

more predators = prey decline

Question 26

graph in Horizontal direction: bottom box is

Answer 26

less predators - prey increase

Question 27

Equilibrium/zero growth isocline

Answer 27

how many predators needs to be present in an area for the prey population to be stable

Question 28

graph in Vertical direction: Left box is

Answer 28

less prey = predators decreases

Question 29

graph in Vertical direction: Right box is

Answer 29

more prey = predators increase

Question 30

Joint Population Trajectory

Answer 30

how a change in one population affects the other

Question 31

Yellow zone (bottom left box)

Answer 31

predator and prey populations are both Increasing; an increase in the prey population allows an increase in the predator population

Question 32

Green zone (top right box)

Answer 32

predators still have enough prey to feed on, but prey population decreases; an increase in the predator population causes a decline in the prey population

Question 33

Blue zone (Top left box)

Answer 33

not enough prey to support predator population; a decrease in the prey population causes a decrease in the predator population

Question 34

Green zone (Bottom left box)

Answer 34

a decrease in the predator population allows an increase in the prey population

Question 35

Lotka-Volteraa Models of Predator-Prey Interactions does not

Answer 35

- account for density-dependent factors or any effects of delayed density dependence - account for often complex foraging strategies of predators

Question 36

What is Functional Responses?

Answer 36

How a predator rate of food changes depending how their food consumption changes - Prey density vs rate of food consumption

Question 37

TYPE I Functional responses

Answer 37

- linear consumption until satiation - rare

Question 38

TYPE II Functional responses

Answer 38

- consumption slows as satiation approaches, as they consume more, handling time increases

Question 39

TYPE III Functional responses

Answer 39

- consumption greatest at moderate prey densities, slows as satiation approaches

Question 40

Why is consumption also slow at low prey densities?

Answer 40

- prey hide in refuge ( small population, so its easier for them to hide from predators) - predators are not well practiced at catching prey when density is low - prey switching to what is more abundant