Predator-Prey Interactions

Question 1

Why doesn’t a prey adopt aposematism when they aren’t actually dangerous?

Answer 1

This does happen sometimes, but predators sometimes test truth of this.

Question 2

What are pursuit deterrent signals? Why do these make sense?

Answer 2

Eg. birds singing instead of flying, gazelle jumping instead of running

Signals that the predator won’t catch the prey

Makes sense for the predator because it wants to avoid wasting chases

Question 3

How did predator-prey ‘communication’ evolve? When can pursuit deterrence signals evolve?

Answer 3

Signals that the predator won’t catch the prey

Makes sense for the predator because it wants to avoid wasting chases

Pursuit deterrence signals can evolve if chases are costly but not too costly.

Question 4

How do anti-predator adaptations affect the prey choice model?

Answer 4

Search time: Affected by adaptations to evade detection (crypsis, polymorphism etc.)

Handling time: Affected by aposematism (warning coloration to signal unprofitability) and pursuit deterrence behaviours

Question 5

Searching for prey

What are predator adaptations and counter-adaptations by prey?

Answer 5

Predatory:

• Improved visual acuity
• search image
• Search limited area where prey abundant

Prey

• Crypsis
• Disruptive patterns
• Countershading
• Polymorphism
• Spacing out (less density = harder to see)

Question 6

Recognition of prey

What are predator adaptations and counter-adaptations by prey?

Answer 6

Predator
- Learning

Prey

• Masquerade (resembling inedible objects)
• Aposematism
• Müllerian mimicry (two poisonous species mimicking each other)
• Deceive predators by mimicking defended prey (Batesian mimicry)

Question 7

Catching prey

What are predator adaptations and counter-adaptations by prey?

Answer 7

Predatory

• Secretive approach
• Motor skills (speed and agility)

Prey

• Signal to predator that it’s been detected
• Escape flight
• Startle response
• Weapons of defense or attack deflection

Question 8

Handling prey

What are predator adaptations and counter-adaptations by prey?

Answer 8

Predator
- Detoxification ability

Prey

• Active defence
• Spines
• Tough integuments
• Toxins

Question 9

What are three reasons for prey tending to be so specialized compared to predators?

Answer 9

• Fewer types of predator than prey
• Generally, shorter generation times of prey
• Life-dinner principle (selection on prey more intense as you go down the food chain)