Lecture 12- Conflict and aggression II Flashcards
what is V/c
a benefit/cost ratio, derived from -rB+C>0- if it is over 1, the behaviour may evolve
when can a mixed dove/hawk population be stable
if the costs of fighting exceed the value of the resource- otherwise, a whole population of hawks is more beneficial
how does frequency-dependent selection work
more hawks- fight costs increase, therefore giving an advantage to being a dove
more doves- can be outcompeted more by hawks as there is less cost to them taking resources- advantage to being a hawk
therefore the frequency of both is maintained at an equilibrium level
example of polymorphisms in aggression within a species
bird species- red morph is rarer, but is successful in breeding site contests due to higher aggression
black morph which has an advantage if red becomes more common, as it does not have to deal with costs of aggression
war-of-attrition model of conflict
whichever animal can withstand the costs of a behaviour for longer wins the contest- involves variations in ‘giving up times’
shape of the graph of giving up times
negative exponential distribution- giving up gets increasingly unlikely as time passes
what changes the position of the curve
higher cost- more likely to give up faster, higher benefit- more likely to wait it out and vice versa
what does the war of attrition model assume
equal resource holding potential- ‘symmetric fighting’, but in reality this plays a part in competition
what is sequential assessment
a model involving 2 animals differing in resource holding potential, which continually try and predict the outcome of competitions- often leads to giving up once a ‘threshold’ is crossed
when will individuals persist?
when benefit no longer exceeds cost- can end up with the higher RVP individual giving up first, due to chance interactions
progression of fights under this model
proceed in steps, and involve behavioural escalation until one party gives up- can be discrete phases, e.g. lions roaring, deer parallel walking before actual fighting
how is signalling useful under the sequential assessment model
avoids the costs of assessing an individual twice, can learn to avoid some individuals etc
when will killing evolve
when killing an individual more than doubles the success of the killing individual
example of understanding future fitness payoffs and how this can impact aggressive behaviour
where there are strict dominance hierarchies, lower down individuals can be less aggressive as there is little benefit to aggression
how does territory impact aggression
residents of a territory should have higher RHP, which makes them more likely to win fights
