Allgemeine Tiere - 6. Räuber-Beute

Question 1

real predetor - parasitoide

Answer 1

kills its prey (also: squirrl with nuts)

Question 2

grazing parasites (weidegänger)

Answer 2

using only part of the prey

Question 3

7 methods for prey to protect itself from predetor

Answer 3

1. active defence: poison
2. mimikry of dangerous species
3. passive: spikes + armor
4. mimesa - blending in environment
5. intimidation (butterfly)
6. swarm behavior - many individuals group and move togather
7. passive: storeing poision, warning colors

Question 4

Why do predetors don’t turn more effective during evolution?

Answer 4

1. many unstable predetor-prey relataionship, but both extincted. [impossible to confirm]
2. predetors can be wise and eat only k/2 of prey so it can survive [against the natural selection]
3. red queen/ army race: organisms must constantly adapt to survive while pitted against ever-evolving opposing organisms in an ever-changing environment

Question 5

When are predetor-prey realtionship stable?

Answer 5

1. BOTTOM UP REGULATION: what affects the prey is external and not the predetor. e.g. Food.
2. when the predetor is not very efficient.

Question 6

When are predetor-prey realtionship unstable?

Answer 6

1. when predetor is very efficient. (TOP DOWN REGULATION)
2. when K for prey is limited.
3. when growth rate of prey is limited.
4. when the initial populations are small.

Question 7

when can prey increase its growth rate?

Answer 7

inefficient predetor / good protection

Question 8

when prey can’t increase its growth rate?

Answer 8

when its at k or when he can’t reduce the amount of deaths that are not connected to predetor.