Deck 15: Aggression

Question 1

Which two variables are common to all game theory models of aggressive contests?

A) resource value and territory size
B) relatedness and ownership
C) territory size and relatedness
D) ownership and contest costs
E) contest costs and resource value

Answer 1

contest costs and resource value

Question 2

Which of the following answers best describes the ESS for the hawk-dove game when V > C; V < C?

A) Dove is the only ESS; dove is the only ESS.
B) Hawk is the only ESS; equilibrial frequency of hawks and doves.
C) Equilibrial frequency of hawks and doves; hawk is the only ESS.
D) Hawk is the only ESS; hawk is the only ESS.
E) Dove is the only ESS; equilibrial frequency of hawks and doves.

Answer 2

Hawk is the only ESS; equilibrial frequency of hawks and doves.

Question 3

Which of the following is NOT a key prediction of the sequential assessment game?

A) Contests are characterized by a series of increasingly escalated bouts.
B) Repeating signals within each bout decreases random error and increases assessment accuracy.
C) The costs of fighting are minimal.
D) Contests should begin with the least dangerous behavior.
E) Contests between well-matched opponents should be longer than contests between individuals that differ considerably in fighting ability.

Answer 3

The costs of fighting are minimal.

Question 4

Animals that adopt antibourgeois strategies:

A) play dove when owner, hawk when intruder.
B) play hawk p proportion of the time and dove 1 ? p proportion of the time regardless of territorial status.
C) play hawk when owner, dove when intruder.
D) play dove when occupying high-quality territories, dove when occupying low-quality territories.
E) play dove when occupying high-quality territories, hawk when occupying low-quality territories.

Question 5

In a group of four individuals (A, B, C, and D), a linear hierarchy emerges when:

A) A beats B and C; B beats C and D; C beats D; D beats A.
B) A beats B, C, and D; B beats D; C beats B and D; D beats no one.
C) A beats B, C, and D; B beats C and D; C beats D; D beats no one.
D) A beats B, C, and D; B beats C; C beats D; D beats B.
E) A beats B; B beats C and D; C beats A and D; D beats A.

Question 6

Which of the following assumptions/predictions apply to the war of attrition model?

A) Contest costs are substantial.
B) There is an evolutionarily stable distribution of contest lengths.
C) The strategy set is discrete rather than continuous.
D) Cues such as size and ownership can be used to settle a contest.
E) a and c

Question 7

Bystander effects occur when:

A) winning a contest increases the probability of winning future contests.
B) individuals change their fighting behavior if they are watched.
C) losing a contest decreases that probability of winning future contests.
D) bystanders actively interfere with the aggressive interactions between two conspecifics.
E) the observer of an interaction changes its assessment of the fighting abilities of those that it observed.

Question 8

One of the most important aspects of Hsu and Wolf's study on winner and loser effects in Rivulus marmoratus was that:

A) winner effects were significantly stronger than loser effects.
B) previous winners experience an increased probability of winning against previous losers but not against inexperienced opponents.
C) both an animal's most recent and "next to last" experience affected future contest success with recent experiences being more influential.
D) fighting experiences obtained in the distant past explained close to all of the variation in current winning probabilities.
E) the probability of winning future fights depended only on an animal's most recent fighting experience.

Question 9

Which of the following statements regarding the effects of serotonin on aggressive behavior is true?

A) Serotonin elicits the same profile of aggressive behavior across all taxa.
B) Low social status decreases serotonergic activity in Atlantic charr.
C) Serotonin is not involved in the expression of aggressive behavior in mammals.
D) Increased serotonergic function is correlated with increased aggression in crustaceans.
E) Hierarchy status is the only type of social and/or environmental stimulus that elicits changes in serotonergic activity in animals.

Question 10

Schuett's research on corticosterone and fighting in copperhead snakes (Agkistrodon contortrix) demonstrated that:

A) losing males do not court available females.
B) plasma corticosterone levels were significantly greater in losers than in winners or controls.
C) losing males rarely challenged other males.
D) circulating corticosterone levels were not influenced by contest length.
E) all of the above

Question 11

Do you think past fighting experience affects social animals in the same manner as it affects solitary animals? Provide a hypothesis that addresses why winning or losing experiences would have the same (or different) effects on solitary versus social animals.

Question 12

Read the article by Innocent and colleagues (2011) titled "Lethal Combat over Limited Resources: Testing the Importance of Competitors and Kin" (Behavioral Ecology, vol. 22, pp. 923-931) and review your answer to Discussion Question 1. Fatal fighting is expected to occur only when the value of the currently contested resource is much greater than the value of resources that could be obtained in the future. How might levels of competition and kinship alter these predictions? Describe how the results of Innocent et al. (2011) speak to this issue.

Question 13

Why would some animals in a population opt to observe aggressive contests rather than engage in actual physical combat? Develop at least two independent hypotheses regarding the conditions or contexts in which watching fights between others be advantageous? Here, you should think about the social environment, physical environment, and the "state" of the observer (e.g., sex, age, health, status).

Question 14

This chapter describes bystander effects as situations in which individuals change their estimation of the fighting ability of those whose fights they observe. Do you think information other than that provided by visual cues is available to a bystander? Also, based on previous chapters, do you think bystander effects could operate in other social contexts, such as mate choice, foraging, cooperation, habitat selection, and territoriality?

Question 15

Levels of steroid hormone (e.g., testosterone, corticosterone) are related to the dynamics and outcome of aggressive disputes in many animals. However, are steroid hormone levels the cause or the consequence of aggressive interactions? For example, do animals with high testosterone levels become dominant, or does dominance status result in elevated testosterone levels? Devise an experiment to test these two alternatives.

Question 16

Review the article by Arnott and Elwood (2009) entitled "Assessment of Fighting Ability in Animal Contests" (Animal Behaviour, vol. 77, pp. 991-1004). In Chapter 15 of Principles of Animal Behavior, you were introduced to the sequential assessment model, wherein animals evaluate the strength of their opponent through a process akin to statistical sampling. What other types of assessment strategies might animals use? How would you discriminate among these assessment strategies experimentally? Design an experiment that would allow you to evaluate, unequivocally, which assessment strategy your organism employs during aggressive contests.