Predator-Prey Avoidance

Question 1

What are two strategies to avoid going extinct due to predation?

Answer 1

Defense
Refugia

Question 2

What is defense?

Answer 2

Stay and don’t get eaten in the first place

Question 3

What are refugia?

Answer 3

Seek refuge from predators

Question 4

What is fight back?

Answer 4

Mobbing or attacking predator through chemical or mechanical means
Learning experience for predator

Question 5

What is aposematic strategy?

Answer 5

Bright or conspicuous coloration displayed by many toxic or distasteful potential prey species

Question 6

What is Mullerian mimicry?

Answer 6

Mimicking of warning signals among different poisonous species

Question 7

What is Batesian mimicry?

Answer 7

A type of mimicry by non-toxic species to resemble toxic species

Question 8

What is spatial refugia?

Answer 8

Seek refuge where predators cannot find you

Question 9

What are the costs to reaching refugia?

Answer 9

Costs energy and hampers foraging opportunities but fitness benefits outweigh the costs

Question 10

What is protection in numbers?

Answer 10

Have populations so large that the risk of any one individual being eaten is low

Question 11

What happens when predator and prey are put in water (Gause’s experiment)?

Answer 11

Did not result in oscillations predicted by the Lotka-Volterra predatory-prey model
Prey and predator go extinct

Question 12

What happened when Gause created refugia for prey?

Answer 12

Prey are able to hide effectively so that they predator died

Question 13

What happened when Gause created immigration by restocking the prey population?

Answer 13

Oscillations occurred as predicted by the Lotka-Volterra models
Immigration created artificially = critique

Question 14

What is the rescue effect?

Answer 14

individuals from larger populations may immigrate and rescue smaller populations

Question 15

What are the pros and cons of being big?

Answer 15

Pro = too big to be eaten
Con = takes a lot of energy to maintain large body size

Question 16

What traits will plants select for (avoidance)?

Answer 16

Make them less likely to be eaten (resistance)
Reduce the harm while being eaten (tolerance)

Question 17

What are constitutive defenses?

Answer 17

Produced continuously, regardless of what happens to the plant

Question 18

What are induced defenses?

Answer 18

Concentrations of a defensive chemical increase rapidly in response to herbivore damage

Question 19

What are examples of constitutive chemical resistance?

Answer 19

Toxins
Digestion-reducing compounds

Question 20

Why are plants with toxic alkaloids more represented in the tropics than in temperate regions?

Answer 20

Tropical areas have more diverse communities of herbivores
Greater variety of herbivores = greater variety of defenses needed

Question 21

Herbivory decreases with what?

Answer 21

Latitude

Question 22

Why don’t plants have warning coloration?

Answer 22

Plants other than green would lead to less photosynthesis

Question 23

Why is fruit not selected against?

Answer 23

Eating ripe fruit does not damage plants
There should not be selection against it from the standpoint of herbivory avoidance

Question 24

Why should flower colour not be selected against?

Answer 24

Flower colour displayed by plant species attracts pollinators

Question 25

Why are there toxic fruits?

Answer 25

They are usually toxic because they are not ripe yet, to reduce the risk of seeds being digested, to facilitate seed dispersal by frugivores

Question 26

What is overcompensation?

Answer 26

Increased plant growth following herbivory, compared to growth of plants that did not experience herbivory

Question 27

What causes overcompensation?

Answer 27

Light grazing = removal of dead plant material
Feces act as a fertilizer
Grazing early in summer