Agonistic Behavior. Agonistic behavior includes a variety of threats or actual combats that settles disputes between individuals in a population.

Agonistic behavior may cause injuries.

This behavior is used to maintain social order such as dominance hierarchy and territoriality.

Territorial Behavior

Territoriality is a defense of an area by an organism against the members of different or the same species.

There is a set of threats displayed between the owners of different territories.

Despite the apparent conflict and aggression associated with territorial behavior, actual fighting is rare.

Because once a territory is established, boundaries are recognized and respected.

This behavior is seen in arthropods, worms, fishes, birds, and mammals.

Territorial behavior among mountain gorillas

Gorillas are highly social and relatively non-territorial.

They live in groups called troops.

The oldest and strongest adult male is called the silverback and is the dominant one in the troop.

He has breeding rights with the females.

Adolescent females transfer to different troops once they reach the age of eight years.

Adolescent males, on the other hand, stay in the troop until they can leave and establish their own troop on their own as the silverback.

Gorillas exhibit territorial behavior by standing on their bottom two legs and pounding their chest to intimidate the threat they have been given.

This threat is not violent and is for the show.

Dominance Hierarchy

Agonistic Behavior. Each animal group establishes a rank that determines its access to resources.

The dominant individuals access resources needed for reproduction, food, space, and mates.

In some animals, dominance is a simple function of aggressiveness which is itself often influenced by sex hormones.

An example is the social hierarchy of chicken.

If several hens, unfamiliar with each other are put together, they will respond by chasing and pecking each other.

Eventually, they establish a “peck order”.

The alpha or first-ranked hen in the pecking order is dominant.

She is not pecked by other hens and drives every hen off by threatening them.

The alpha hen also has first access to resources like food, eater, and rooting sites.

The beta or second-ranked hen similarly subdues all others excerpt alpha hen and so on down the line to the omega, or the lowest-ranked hen.