6. Predator-Prey Interactions

Question 1

Prey Strategies for Predator Evasion

Answer 1

Prey use strategies like camouflage, reduced activity, and hiding.
Avoiding capture involves evasion, aggregation, harassment, and aggression.
Other tactics include chemical defenses and coloration.
Examples: Stick insects, color-changing geckos, and leaf-tailed geckos employ camouflage to elude detection by predators.

Question 2

Absence of Antipredator Behaviours

Answer 2

Predator avoidance is costly for prey.
In predator absence, selective advantage for these behaviors diminishes.
Costs include metabolic costs and missed opportunities.
Relaxation of selection occurs when predators are isolated.
Example: Guppies show coloration changes based on predator presence, highlighting the impact of predator absence on antipredator behaviors.

Question 3

Anthropogenic Influences on Predator-Prey

Answer 3

Human activities introduce/remov predators, altering interactions.
Yellowstone: Wolf reintroduction impacted elk, plant, beaver dynamics.
Multipredator hypothesis: Multiple predators can aid coping.
New Zealand: Lack of predator history affects introduced predators’ impact.

Question 4

Trade-offs and Predation Risk

Answer 4

Predation risk creates foraging trade-offs.
High-energy needs may lead to riskier foraging.
Example: Redshanks exhibit riskier foraging in colder weather due to energy requirements.

Question 5

Anthropogenic Landscape Changes

Answer 5

Human actions (forestry) affect predator-prey interactions.
Habitat alterations impact predation patterns.
Insights help address human-wildlife conflicts.
Example: Yellowstone’s wolf reintroduction triggered ecosystem changes impacting elk, beavers, and plants.

Question 6

Conclusion: Insights into Predator-Prey Dynamics

Understanding Antipredator Strategies

Answer 6

Prey use evasion, aggregation, and more to evade predators.
Absence of predators can lead to relaxed antipredator behaviors.
Anthropogenic activities alter predator-prey interactions.
Trade-offs involve foraging decisions under predation risk.
Landscape changes impact predation patterns.
Knowledge aids resolving human-wildlife conflicts.
Wolf reintroduction in Yellowstone showcased ecosystem impacts.