Chapter 14 - Aggression In Animal Behavior

Front 1

Elephants and aggression

Back 1

have a super long gestation period – elephant uses low frequencies to find a mate. She makes a call and all of the males who are trying to mate with her fight with each other “oozing with a reproductive urge” this test allows her to find the biggest strongest male.

Front 2

Dominance Hierarchy

Back 2

Alpha has most access to food and resources and mating
then Beta
then Gamma

Front 3

proximate underpinnings of aggression

Back 3

androgens (testosterone) and glucocorticoids

Front 4

proximate explanation of alpha individuals

Back 4

1. higher androgens make them more aggressive
2. heightened glucocorticoids because they have to be more nervous about defending their status and territory

Front 5

proximate explanation of lower ranked individuals

Back 5

higher levels of glucocorticoids

Front 6

fight or flight response

Back 6

1. norepinephrine & adrenaline. Quick increase in blood sugar and oxygen delivered to brain, skeletal muscles, and heart. Non essential system shut down. A similar, less dramatic, response occurs when animal encounters aggressive individual from own population

Front 7

ultimate underpinning of aggression

Back 7

when the benefits of victory (on average) outweigh the cost of fighting, its predicted they will fight

Front 8

atlantic salmon

Back 8

1. higher ranked males have dark vertical lines by the eye
2. subordinates have darker eye color.
3. fish have tight control over pigment cells affected by hormones

Front 9

serotonin and agression

Back 9

1. mammals: low = more aggressive, lower rank
2. fish: high = less aggressive, lower rank
3. crustacean: high = more aggressive, higher rank

Front 10

game theory models of aggression and what do all three models assume?

Back 10

1. Hawk-Dove
2. War of Attrition
3. Sequential Assessment

Front 11

Hawk- Dove

Back 11

1. Hawk/Hawk - 50% chance of obtaining resource and being injured... Payoff = (V-C)/2
2. Hawk/Dove - dove will back off so hawk payoff = v and dove payoff = 0.
3. Dove/Dove - Each take half avoid fight...Payoff = v/2

Front 12

bourgeois strategy

Back 12

1. individual plays hawk if they are a territory holder, plays dove if not
2. speckled butterflies

Front 13

speckled butterflies

Back 13

1. sunny patches and the bourgeois strategy
2. As these territories are short lived, it is not worth the cost to fight.

Front 14

anti-bourgeois strategy

Back 14

1. territory holder always leaves
2. mexican spiders
3. not worth it to fight because theres many available territories

Front 15

War of Attrition

Back 15

1. Game theory model of aggression
2.Time of aggression is probability function based off the value of the resource. (2/V)e^-2x/v (exponential function)
3. Each competitor suffers a cost
4. Dung flies and mating

Front 16

Assumptions of War of Attrition Model

Back 16

1. individuals choose to display for any amount of time
2. behavior is costly
3. no clear cues such as size should settle the contest

Front 17

Sequential Assessment Model

Back 17

1. individuals continually assess one another in a series of bouts
2. start with least dangerous behavior and learn all about it. work your way up to become more confident
3. shorter contests see fewer types of behavior

Front 18

Sequential Assessment Model of Aggression in Fish

Back 18

1. change color (least dangerous)
2. Approaching/tail beating
3. circling
4. fights last longer with better matched pairs & heavier fish win easily. High weight diff = shorter fight

Front 19

Winner Effect

Back 19

1. Beating Meryl will make me more aggressive the next time I fight her
2. Increased glucocorticoids are sometimes seen in winners, but winners typically return to baseline levels faster

Front 20

Loser affect

Back 20

1. Losing to Meryl will make me less aggressive next time around because I'll be less confident
2. Loser effects are more common than winner effects
3. Losers tend to have suppressed testosterone, whereas winners tend to have higher levels

Front 21

Blue Footed Boobies

Back 21

1. Hierarchy appears between nest mates
2. Even if submissive grows larger than dominant, it remains submissive. When paired with neutral, there were strong winner and loser effects
4. Winner effects wore off but loser effects remained

Front 22

Fish and Winner/Loser Effects

Back 22

1. Studied penultimate interactions
2. Penultimate did have an effect, but not as strong

Front 23

Copperhead Snakes and Winner/Loser

Back 23

1. No winner/ Strong Loser effects. 2-time losers lose all contest even against smaller opponents
2.These snakes act subordinate, rarely challenge other males, and rarely court females in the vicinity of where they fought. (Aggression and mating success)

Front 24

RHP

Back 24

1. Resource Holding Power
2. The fighting ability of an individual

Front 25

Mathematical Models of Aggression need to account for:

Back 25

1. RHP
2. Winner effects - hierarchies where rank is easy to define because there will be more fighting
3. Loser effects - where there is a clear alpha, but all other roles are murky

Front 26

Bystander (aka eavesdropper) Effect

Back 26

1. Observing two other individuals changes their estimation of fighting ability of those individuals
2. Bystanders will typically try to avoid individuals that they have seen win a fight
3. unclear as to results if you watch someone lose

Front 27

Audience Effect

Back 27

1. Knowing people are watching changes behavior
2. Chimps that are losing will emit louder screams if there's an audience.
3. Effect only seen if at least one audience member with an equal of higher rank than the aggressor