L8&9 - Conflict Flashcards
(26 cards)
what is an ESS
evolutionary stable strategy
under what conditions is a strategy considered an ESS
when adopted by a population, cannot be invaded or replaced by any alternative strategy through natural selection, ess is also specific to conditions of game and payoff matrix
what is a typical example of a choice between different strategies of conflict behaviour
dove x hawk, either always escalate or display and retreat if opponent escalates
what is considered as a pure strategy
always play a specific tactic (eg always hawk
what is considered mixed strategy
play tactic with a fixed probability
what is the difference between mixed and pure ESS
pure ess means there is one strategy fixed in the populations as it is unbeatable, a mixed ess is that there is a combination of 2 pure strategoes at specific population frequences OR mixed strategies where each individuals plays hawk and dove a certain percentage of the time
define strategy
a genotype determining a behaviour or a set of behaviours
define tactic
behavioural phenotype of a strategy
what is the payoff when 2 hawk strategies meet
(value of resource - injury costs) /2
what is the pay off for hawk and dove if they meet
hawk - value of resource
dove - 0
what is the pay off when 2 doves meet
Value of resource divided by 2
explain why pure dove is never an ESS
in a population doves, hawk will always be a superior strategy so it would invade a population of doves
explain under which conditions pure hawk is an ESS
if value of resource is larger than costs, because hawk is the best strategy against hawk opponent and always wins against a dove
when does mixed ESS of 2 pure strategies occur
when value of resource is smaller than costs, therefore there will be frequency dependent payoffs, has an ESS equilibrium frequency where the average payoff of both strategies is equal, this value is what all populations evolve towards
explain what asymmetry is in conflicts
real conflicts will be asymmetrical, observed by resource holdng potential (RHP), which is dictated by absolute fighting ability of individual (many physical factors but also experience and ability to use them)
how would the frequency of hawk and dove be calculated given the costs and value,
by calculating total payoff for each scenario, adding together both scenarios for hawk and dove, then set them at = (because equilibrium) and solve for hawk frequency by calculating h
what can determine the roles opponents are going to play ina conflict
assessor or bourgeois - assessor when weaker plays dove and stronger plays hawk, bourgeois when owner of resource plays hawk and intruder plays dove
explain how the example of speckle wood butterfly relates to hawk-dove-bourgeois
if value is smaller then cost, the owner will always be hawk and intruder always dove, if value of resource is greater than cost everyone will play hawk (ESS)
what are the three fighting strategy models
sequential assessment (SAM)
energeticwat of attrition (EWOA)
cummulative assessment (SAM)
what is the core idea of SAM and give an example
individual decides how long to fight based only on its own abilities or costs incurred during the fight. The animal continues until it reaches its own internal threshold, fight duration depends on losers resource holding potential (higher rhp of loser means longer fight, example is jumping spiders where level of escalation decreases with greater RHP difference
what is the core idea of EWOA and give an example
war of attrition model that incorporates energy expenditure into decision-making. It assumes individuals don’t fight by inflicting damage, but by persisting—whoever holds out longer wins. Each animal randomly chooses how long to persist based on its energy reserves, choice to continue depends on current energy capacity, no assessment of opponent (probabilistic), example ebony jewelwinning or butterflies that circle each other (winners will have higher fat reserves)
what is the core idea of CAM and give an example
assumes each animal monitors the total costs it accumulates from both its own actions and the opponent’s, Loser gives up when its cumulative cost threshold is reached, not necessarily its own effort., example is crab might stop fighting because the opponents attack have drained its stamina, not just its own effort, depends on both contestants RHP
what are the dear enemy and nasty negihbour hypothesis
how a conflict is escalated if individual knows or does not know intruder
what is the dear enemy hypothesis
territorial animals will show reduced aggression towards neighbours in comparison to unknown intruders, because neighbour is already established thus unlikely to take over territory, example of great tits that have reduced attacks/singing when hearing a neighbours song compared to a strangers
