Predator-Prey Interactions

Question 1

What is the red queen hypothesis?

Answer 1

“Continuing adaptation is needed in order for a species to maintain its relative fitness amongst the systems it is co-evolving with”

Question 2

What are the selection pressures in predators?

Answer 2

Selection for improvements in foraging

Question 3

What are the selection pressures in prey?

Answer 3

Selection for improvements in defences

Question 4

What are the predator adaptations when searching for prey?

Answer 4

Improved visual acuity
Search image
Search limited area where prey abundant

Question 5

What are the counter-adaptations by prey when predators are searching for them?

Answer 5

Crypsis (background matching, disruptive patterns and countershading)
Polymorphism
Space out

Question 6

What are the predator adaptations in recognition of prey?

Answer 6

Learning

Question 7

What are the counter-adaptations by prey when predators are recognising them?

Answer 7

Masquerade (resemble inedible objects)
Warning signals of toxicity (aposematism, Mullerian mimicry)
Deceive predators by mimicking defended prey

Question 8

What are the predator adaptations in catching of prey?

Answer 8

Secretive approach
Motor skills (speed and agility)
Weapons of offence

Question 9

What are the counter-adaptations by prey when predators are trying to catch them?

Answer 9

Signal to predator that it’s been detected
Escape flight
Startle response: eyespots
Deflect attack
Weapons of defence

Question 10

What are the predator adaptions when handling prey?

Answer 10

Subduing skills

Detoxification ability

Question 11

What are the counter-adaptations by prey when predators are handling them?

Answer 11

Active defence, spines, tough integuments

Toxins

Question 12

What is camouflage?

Answer 12

All forms of concealment, including strategies that prevent detection (background matching) and those that prevent recognition (masquerade)

Question 13

What are the two forms of camouflage?

Answer 13

Prevent detection: crypsis (background matching, countershading and disruptive colour)
Prevent recognition: masquerading

Question 14

What is the purpose of background matching?

Answer 14

It makes searching for the prey more difficult for the predator because they do not match their pre-learned “search image”

Question 15

What is countershading?

Answer 15

Animal counters the patterns of light and shade with body colouration: put the darker colours on parts of the body that are typically illuminated - enhances cryptic protection

Question 16

What is disruptive colouration?

Answer 16

Disruptive coloration is a form of camouflage that works by breaking up the outlines of an animal with a strongly contrasting pattern

Question 17

What is prey polymorphism?

Answer 17

It describes the survival of individual prey animals that are different (through mutation) from their species in a way that makes it more likely for them to be ignored by their predators. It operates on polymorphic species, species which have different forms.

Question 18

What is apostatic selection?

Answer 18

Where predators overlook rare prey types and consume excess of abundant prey types

Question 19

What is an example of apostatic selection?

Answer 19

Grouse locust - frequency dependent selection whereby the fitness of morph declines if it becomes too common in the population

Question 20

What is masquerade?

Answer 20

Masquerade describes the resemblance of an organism to an inedible object and is hypothesised to facilitate misidentification of that organism by it’s predators or its prey.

Question 21

How can you distinguish between masquerade and crypsis?

Answer 21

With crypsis, detection of the individual in the environment is reduced; With masquerade the predator detects the existence of the potential prey but then misidentifies it as something unattractive to eat.

Question 22

What are aposematic signals?

Answer 22

Aposematic signals are primarily visual, using bright colours and high-contrast patterns such as stripes.

Question 23

How do aposematic signals sometimes exploit aspects of predator psychology?

Answer 23

Wariness of certain colours/patterns
Capacity to learn
Memory retention of learnt avoidance

Question 24

What is an example of when aposematism has been used in conjunction with spatial behaviour?

Answer 24

Brightly coloured species of caterpillars of British butterflies are more likely to be aggregated in family groups than cryptic species

Question 25

What are the two types of mimicry?

Answer 25

Mullerian and Batesian

Question 26

What is Mullerian mimicry?

Answer 26

Müllerian mimicry is a natural phenomenon in which two or more well-defended species, often foul-tasting and that share common predators, have come to mimic each other’s honest warning signals, to their mutual benefit.

Question 27

What are potential examples of Mullerian mimicry?

Answer 27

Heliconius butterflies, European burnet moths, bumble bees, cotton Stainer bugs, poison arrow frogs, Appalachian millipedes.

Question 28

What is an example of mimicry rings (pairs of multiple species)?

Answer 28

Butterflies
Prey benefits because predators learn avoidance more quickly.
Heliconius cydno has 2 forms, white and yellow.
Each form does better in sites where its model is more abundant
Butterflies released at 4 sites, control (solid line) resemble the model, experimental (dashed) do not.

Question 29

What is Batesian mimicry?

Answer 29

Batesian mimicry is a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both.

Question 30

What is the difference between Batesian and Mullerian mimicry?

Answer 30

Batesian mimicry is the exhibition of the characteristics of a dangerous species by a harmless species to avoid predators whereas Mullerian mimicry is the exhibition of similar characteristics by similar species to avoid predators

Question 31

What is an example of when even poor mimics were good enough?

Answer 31

Coral snakes and nonvenomous scarlet king snakes: replicas of poor mimics were preyed on significantly more often than replicas of perfect and good mimics.
Perfect and good mimics experienced similar attack rates, despite having a different ring order.
Poor mimic – same colours, different proportions, different order
Good mimic – same colours, same proportions, different order
Poor mimic higher probability of attack

Question 32

What is death feigning?

Answer 32

“Playing dead”

Question 33

Death feigning versus flight

Answer 33

Animals like cuttlefish match their response (play dead or flee) to the threat level and predator type