Chapter 17

Aggression

Behavior intended to inflict harm on others.

Agonistic Behavior

Behavior related to conflict and aggression.

Interspecific Aggression

Aggression between different species.

Intraspecific Aggression

Aggression within the same species.

Biological Advantages of Aggression

Secures territory, resources, and mating opportunities.

Testosterone

Steroid linked to male aggression development.

Challenge Hypothesis

Links testosterone levels to aggression in mating contexts.

Seasonal Breeding

Reproductive cycles influenced by environmental factors.

Dehydroepiandrosterone (DHEA)

Abundant androgen hormone affecting aggression levels.

Gonadal Steroids

Hormones regulating aggression during breeding seasons.

Non-Gonadal Steroids

Hormones regulating aggression outside breeding seasons.

Corticosterone

Glucocorticoid hormone promoting aggressive behavior.

Low Corticosterone Levels

Can lead to increased aggression.

Chronic Corticosterone Reduction

May cause abnormally aggressive behavior.

Social Hierarchies

Established through aggression and glucocorticoid levels.

Cortisol

Glucocorticoid linked to stress response and aggression.

Proactive Aggression

Associated with low cortisol levels.

Reactive Aggression

May occur with elevated cortisol levels.

Predator-Prey Interaction

Example of aggression in nature.

Ritualistic Behavior

Non-lethal displays to avoid actual fighting.

Threat Behavior

Signals hostility or intent to attack another animal.

Submission

Indication of non-challenge to a dominant individual.

Agonistic Fighting

Escalation of threat display into actual combat.

Dominance Hierarchy

Social ranking within a group of cooperating individuals.

Resource Competition

Conflict over access to food or mates.

Threat Display

Behavior intended to intimidate an opponent.

Physical Attributes Display

Show of size or strength to deter aggression.

Conciliation

Efforts to resolve conflict without aggression.

Hissing Behavior

Sound made by cats as a threat display.

Intimidation Display

Physical postures to show readiness for aggression.

Bearded Dragon Submission

Visible waving to indicate non-aggression.

Agonistic Interaction

Behavioral exchanges during conflicts between individuals.

Fighting Duration

Contests can last from minutes to over an hour.

Restraint in Fighting

Avoiding injury by not using venom in fights.

Threat Elicitation

Threat behavior triggers responses like submission or fighting.

Agonistic Behavior Patterns

Three types: threat, fighting, and submission.

Ritualized Display

Non-lethal actions indicating size and strength.

Physical Fighting

Rare due to high costs like injury.

Cost-Benefit Analysis

Weighing risks and rewards before engaging in conflict.

Relative Fighting Ability

Assessment of opponent's physical characteristics.

Threat Displays

Non-physical actions to intimidate opponents.

Relative Experience

Past conflict outcomes affecting future confrontations.

Territorial Disputes

Conflicts over control of specific areas.

Social Status

Rank within a group affecting access to resources.

Linear Dominance Hierarchy

Rank structure where higher ranks dominate lower ranks.

Hormonal Influence

Hormones affecting social hierarchies in various species.

Aggression in Groups

Conflict among group members over resources.

Asymmetry in Combatants

Unequal fighting ability leading to conflict avoidance.

Energy Costs of Displays

Displays consume energy and time needed for survival.

Conflict Avoidance

Choosing not to fight when costs are too high.

Paper Wasp

Species Polistes dominulus exhibiting social structures.

Naked Mole-Rat

Species Heterocephalus glaber known for eusocial behavior.

Queen

Highest-ranking female in a dominance hierarchy.

Luteinizing Hormone

Hormone suppressed in sub-dominant males.

Ovarian Cycle Suppression

Prevents reproduction in sub-dominant female mole-rats.

Glucocorticoids

Stress hormones affecting dominance and behavior.

Fight or Flight Response

Physiological reaction to perceived threats.

Reproductive Function

Ability to reproduce, influenced by social rank.

Dominant Individuals

Higher-ranking members with greater resource access.

Subordinate Individuals

Lower-ranking members with fewer resources.

Health Costs of Dominance

Adverse effects like immunosuppression from being dominant.

Sneaker Males

Subordinate males gaining mating access without dominance.

Home Range

Area where an animal performs normal activities.

Core Area

Central part of home range used most frequently.

Territory

Defended area excluding conspecifics from access.

Social Benefits of Subordination

Avoiding costs of dominance while gaining advantages.

Territorial Animals

Species that defend specific areas.

Territoriality

Behavior of defending a resource area.

Mating Site

Area used for breeding activities.

Resource Defense

Protecting resources from competitors.

Display Behavior

Non-aggressive signals to deter intruders.

Scent Marking

Depositing scent to establish territory boundaries.

Pair Defense

Territorial defense by mated pairs.

Group Defense

Territory protection by a group of individuals.

Seasonal Territoriality

Territorial behavior varies by season.

Lek Site

Area defended for mating displays.

Resource Abundance

Availability of resources affecting territoriality.

Resource Distribution

Spatial arrangement of resources influencing defense.

Intruder Pressure

Competition level impacting territory defense costs.

Territory Size

Area size determined by resource availability.

Group Territory Sharing

Multiple individuals share and defend a territory.

Easier Defense

Choosing territories that are simpler to protect.

Neighbor Warnings

Alerting nearby territory holders of intruders.

Defined Boundaries

Clear markers to reduce defense costs.