PCE - 5

Question 1

how does competition create differences?

Answer 1

evolution of traits that minimise overlap of habitat/ resource use

Question 2

why is predation important in ecology?

Answer 2

affects structure and dynamics of communities

Question 3

why is predation important in evolution?

Answer 3

affects morphology, physiology, behaviour

Question 4

why is predation important in agriculture?

Answer 4

the need for pest control; pesticides

Question 5

why is predation important in conservation?

Answer 5

predator control vs. reintroductions;

pesticides

Question 6

why is predation important in biodiversity?

Answer 6

has an affect on richness, eveness, diversity, gradients

Question 7

what are the components of the optimal foraging theory?

Answer 7

• Objective: maximise profitability (energy/time)
• Currency: unit to maximise (energy etc) profitability (energy/time)
• Constraints: search time and handling time (cant search will handling cant eat while searching)

Question 8

what is the equation for diet breadth - when an organism should add a new item to their diet?

Answer 8

profit of new prey >= cost of ignoring new prey and searching for another of most profitable

Question 9

what is diet breadth (contigency model of foraging)?

Answer 9

• Choose most profitable, ignoring search costs.

- Add items until the profit of new items is less the average cost of searching and handling items currently in the diet

Question 10

What are the two constraints that determine

whether an item is included in the diet?

Answer 10

handling and search time

Question 11

what is the definition of random eating?

Answer 11

eat in proportion to what is available

Question 12

does profitability = abundance?

Answer 12

no

Question 13

what does prey death function =?

Answer 13

= predator growth function

- conversion of prey into predators

Question 14

what is a functional response?

Answer 14

how predator consumption varies with prey density

Question 15

what does consumption rate by predator =

Answer 15

= mortality rate for the prey

Question 16

what are the 3 functional responses?

Answer 16

1) Constant Mortality Rate
2) Mortality Rate DECREASES with Density
3) Mortality Rate INCREASES then DECREASES with
Density

Question 17

describe type 1 function response?

Answer 17

consumption rate and prey density increase exponentially - the gradient is constant therefore prey mortality is also constant - straight line

Question 18

describe type 2 function response?

Answer 18

inverse density dependent mortality - no negative feedback in prey mortality
- most common

Question 19

describe type 3 function response?

Answer 19

logistic model - density dependence is acting- negative feedback - gradient increases then reaches inflection point and starts decreasing

Question 20

what is the recipe (outcome of species interactions)?

Answer 20

1) choose a growth function (exponential or logistic)
2) choose a functional response (type 1, 2 or 3)
3) convert the functional response to numerical (multiply by 10%)
4) choose a predator death function

Question 21

what 3 affects can predation have on diversity?

Answer 21

1) Keystone predation increases diversity
2) Generalist predation can decrease diversity
3) Predation can change ranking of competitors, but not change diversity