8 Flashcards
What can tactics depend on
Condition and enviro cues
H vs H
V-c/2
H vs D
V
D vs H
0
D vs D
V/2
If …. Pure hawk is ESS
V > c
What happens if v
Means each strategy is best to fight other so no ESS which explains mixed pops here a mixed strategy may be sand ESS
F*
Evolutionary stable equilibrium frequency
V
Value of resource
C
Cost of resource
Hawk strat 1 and dove strat 2
Hawk - always escalates and retreats only if injured
Dove - retreats immediately if component escalates
Average payoff playing Hawks is h = frequency of Hawks
H ( HvsH ) + 1-h ( HvsD)
Average payoff for dove if h = freq if Hawks
H-1( DvsD) + h(DvsH)
When is ESS wrt to average payoff
When average payoff playing dove = average payoff playing hawk
Why is dove hawk game not realistic 4
In real life More than 2 strats Asymmetries occur --> fighting ability (strength/size) --> RHP resource holding potential --> experience and motivation
What may evolve because hawk dove no realistic
Assessment strats
Ritualisation
Is crickets and red deer
Other 2 models hawk dove
Bourgeois
Assessor
Bourgeois
Maynard smith
Plays hawk if owner and dove if intruder
Assessor
Lamar and enquist
Plays dove if weaker and hawk if stronger
What cues can defending I’d fight or withdraw 3
Badges of status
Threat display
Injuries
SAM
Decision based in info about opponent relative to self
Assessment of opponent
No matching behaviours needed
Escalation sequentially
Sam contest duration
Correlates with RHO asymmetry between opponents and does not increase with mean opponent RHP
SAM display characteristics
Non dangerous index symbols
But ritualistic fighting tactics
Sam examples 2
Red deer -assess parallels walk and make roar rate this is correlated with opponents and usually occurred when no size dif
Similarly in jumping spiders escalation linked to body size as there is only correlation if little or no difference if big difference no escalation
CAM decisions
Based on costs relating from own actions and inflicted by opponent
No opponent assessment and no matching behaviours
But escalation or descant ion avail ale WITHIN a phase
CAM fight duration
Correlates with loser RHP AND winner RHP
Duration does increase with mean opponent RHP
Cam displays?
Yes and dangerous
Define what an ESS is
Evolutionary stable strategy
When adopted by most members of the population cannot be invaded by spread of a rare alternative
CAM examples
Acheta domesticus
Winner wight and loser weight explain the duration of agrees ion - best predictors
Gryllus pennysylvanicus
Stereotypic escalation is afresh in depends on size and winner sings
Large make one 75% of fights and accumulating fighting costs were witnessed as fighting became more sever
Get loud pennysylvanicus engagement ranks 5
Antennal fencing Mandibles spread unilaterally Then bilaterally Mandible engagement Grappling
Ewoa decisions
Decisions based on costs from own actions and does require ENERGY MATCHING and escalation can be possible within phases
Ewoa contest duration
Correlates with loser RHP and does increase with mean opponent RHP
Ewoa display
Energetically costly grappling and handicap signals with forced matching
Ewoa example
Dragonflies
V territorial Arian display and retreats when runs out of energy therefore the winners have greater fat content and loser quit time depends on self assessment of fat
Fatal fighting is trade off between
Present potential fatal fight for massive rewards
Future survivorship and fecundity
Fatal fighting prediction
Occurs in species with Hirt lifespans and few repor opportunities and studies therefore show mostly in Arthropods tha mammals
Or wingless make ground fig wasps - f mate once so limited resource makes fight to death using horns
2 examples fatal fight
Wingless make torymid wasps -fight to death using horns
Ant queens in ladies Niger
7/16 fights had f dying after list fight
