competition for resources

Question 1

intraspecific competition

Answer 1

interaction between individuals within same population
can lead to reduction in fitness for both participants

Question 2

what are resources

Answer 2

general term for materials that are required and influence fitness

energy
food
water
mates
territories

currency of proximate costs and benefits in fitness

Question 3

ESS ?

Answer 3

Stable outcome of competition

if all members of a population adopt it, can’t be bettered by alter. strategy

Question 4

difference between strategy and tactic?

Answer 4

strategy: genetically based decision rule (“always”)

tactic: behavioral pattern played as part of a strategy (“sometimes”)

Question 5

what is the hawk-dove game

Answer 5

two individuals, same species, different strategies
hawks always fight, may injure opponent/self
doves never fight, retreat and share resources with other doves

v = value of resource
c = cost of injury
v < c

both strategies do best when rare
frequency dependent selection

Question 6

how could the ESS hawk-dove arise

Answer 6

stable polymorphic state, pure strategies at 50:50

mixed strategy, randomly choosing p(1/2)

Question 8

if v > c, what is the ESS

Answer 8

hawk is the ESS
(Consider lifetime reproductive success not just current contest)

Question 9

what is the ideal free distribution

Answer 9

assumption: all competitors have complete information about resource availability

assumption: all competitors can freely move between resource patches and exploit patch with higher payoff

prediction: best resource patch depends on where all others go

first arrivals will go to richest > resource depletion > poorer habitats = habitats become the same

Question 10

what does cow pat mate competition depend on

Answer 10

what other males are doing

Question 11

the competitive unit model

Answer 11

What happens to the IFD model when individuals differ in competitive ability?

Question 12

what are conditional strategies with alternative tactics

Answer 12

silent satellite behaviour in natterjack toads
when call volume of neighbour exceeds threshold
can involve morphological switches (long/short-horned dung beetles)

Question 13

what can also arise from alternative genetically encoded strategies

Answer 13

genetic polymorphism
side-blotched lizards rock-paper-scissors game (orange/blue/yellow)
frequency-dependent selection