Chapter 15 Flashcards
does dominance rank impact behavioral decisions
Yes, habitat choice
aggression
agonistic behavior, occurs when animals send threatening signals or engage in some sort of physical combat
dominance hierarchies
rank orderings of the individuals based on the results of pairwise
aggressive interactions
an ultimate perspective of fighting
This decision revolves around the costs and benefits of aggression. When the benefits of victory, on average, outweigh the costs of fighting, natural selection will favor aggressive behaviors
a proximate perspective of fighting
Immediate causation and aggression. When animals opt to fight or flee from others in their own population, ethologists often focus on the endocrinological
underpinnings of such behavior and have found similar hormonal
responses across different species (testosterone more likely to fight)
why are subordinates more likely to flee
because they have more of stress hormones, and therefore they are more likely to lose a fight, but in some cases the dominant loses
fish and color and how it connects to fighting
Color change may be a particularly good communication vehicle in
aggressive contests, because color change can quickly indicate an
individual’s relative rank in a hierarchy and whether it will engage in aggressive behaviors. A fish can change colors to let the other know they are losing. ex: dominant male atlantic salmon develop dark vertical eye bands and subordinate atlantic salmon individuals develop darker body color
what does low serotonin mean in fights
high levels of aggression, prozac can counteract this
what is the hawk dove game
hawk: escalates and continues to escalate until either it is injured or its opponent cedes the resource
dove: displays as if it will escalate, but retreats and cedes the resource if its opponent escalates
3 outcomes
1. hawk vs dove: the hawk receives the entire value of the resource (V),
2. dove vs dove: they receive half the value of the resource (for
example, they split a food item in half).
3. hawk vs hawk: only the loser pays the cost of fighting (for
example, the cost of being injured). Each hawk has a 50 percent chance of obtaining the resource (V/2) and a 50 percent chance of being injured and not receiving the resource
The war of attrition model
The war of attrition model of fighting behavior makes a number of assumptions:
(1) individuals can choose to display aggressively for any duration of time
(2) display behavior is costly—the longer the display, the more energy expended
(3) there are no clear cues, such as size, territory possession, and so forth, that contestants can use to settle a contest
sequential assessment model
designed to analyze fights in which individuals continually assess one another in a series of “bouts”
- Individuals assess their
opponent’s fighting abilities
- the more evenly matched the opponents, the longer the fights
- Aggressive behaviors are used in
approximately the same order across all fights; shorter fights have less behaviors but still the same order
what are winner and loser effects
winner effects: winning an aggressive interaction increases the probability of future wins
loser effects: losing an aggressive interaction increases the probability of losing future fights (increased stress and low testosterone)
bystander effect
occur when the observer of an aggressive interaction changes its assessment of the fighting abilities of those it has observed. Through observation, bystanders learn beforehand something about the opponents they may face in the future
Observers modified their behaviors differently when paired with those they had seen win versus lose a fight
audience effect
individuals involved in aggressive interactions change their behavior if they are watched
Victim scream: This is seen only when at least one of the audience members held a rank in the hierarchy that was equal to or above the rank of the aggressor (so they could help break up the fight)
