Gradually escalating fights and displays: the cumulative assessment model

Area of Science:

• Ethology
• Behavioral Ecology
• Game Theory

Background:

• Animal contests often involve prolonged displays or fights.
• Existing models like the Sequential Assessment Game and War of Attrition describe these interactions.
• A need exists for models that account for cumulative action assessment in dyadic antagonistic encounters.

Purpose of the Study:

• To present a novel 'cumulative assessment model' for dyadic antagonistic encounters.
• To offer an alternative framework to existing models for temporally extended displays.
• To identify how the cumulative assessment model can be distinguished from other models.

Main Methods:

• Development of the 'cumulative assessment model' based on cumulative sums of an adversary's actions.
• Application of the model to ritualized fights and displays with external time costs (e.g., predation risk).
• Comparison of the cumulative assessment model with the sequential assessment model and the war of attrition.

Main Results:

• The cumulative assessment model predicts that losers may initiate encounters at lower intensity but escalate faster than winners under certain conditions.
• This prediction was observed in the cyprinodont fish Aphyosemion striatum.
• The model suggests distinguishability from other models through escalatory properties and intrapopulation variation.

Conclusions:

• The cumulative assessment model provides a new perspective on decision-making in animal contests.
• The model's predictions are supported by observations in Aphyosemion striatum.
• Further research can differentiate between the cumulative assessment model and other models by examining specific behavioral patterns.