Signaling aggression.

Area of Science:

• Ethology
• Evolutionary Biology
• Animal Behavior

Background:

• Aggression is defined differently across disciplines, from intentional harm (psychology/sociology) to escalated attack behaviors (biology).
• Animal signals associated with escalating attacks function similarly to physical aggression in contests.
• Evolutionary pressures have refined aggressive signals for effective mediation of interactions.

Purpose of the Study:

• To review the role of signaling in animal contests as an alternative to physical violence.
• To examine threat displays from an ethological perspective as an adaptive evolutionary outcome.
• To explore how aggressive signals reliably communicate fighting ability and intent.

Main Methods:

• Review of theoretical analyses and game theory models of aggressive signaling.
• Ethological perspective on threat displays and evolutionary selection pressures.
• Case studies illustrating visual and chemical signaling (cephalopods) and auditory signaling (songbirds).

Main Results:

• Contrary to early theories, modern models show aggressive signals can be honest indicators of fighting ability and intent.
• Performance signals convey fighting prowess, constrained by physical ability.
• Strategic signals encode aggressive intent, producible by all signalers.

Conclusions:

• Aggressive signaling is an adaptive evolutionary strategy that can reliably mediate contests and reduce physical violence.
• Threat displays are effective tools shaped by natural selection.
• Diverse sensory modalities are employed in aggressive signaling across taxa.