The evolution of performance-based male fighting ability in Caribbean Anolis lizards

Area of Science:

• Evolutionary biology
• Animal behavior
• Comparative physiology

Background:

• Sexual signals and performance capacity are key in male-male competition.
• Few studies use a comparative approach across species with varying combat intensity.

Purpose of the Study:

• Investigate the roles of dewlap size (sexual signal) and bite force (performance capacity) in male combat outcomes.
• Examine these roles across nine Caribbean Anolis lizard species differing in territoriality (indicated by sexual size dimorphism).

Main Methods:

• Comparative analysis of dewlap size and bite force in nine Anolis lizard species.
• Correlating signal traits and performance with combat success and territoriality.

Main Results:

• Dewlap size honestly signals bite force in dimorphic species, but not less dimorphic ones.
• Bite force predicts combat success in dimorphic species; dewlap size predicts it in less dimorphic species.
• More dimorphic species escalate to biting more readily during fights.

Conclusions:

• Species-specific ecological and behavioral traits modify sexually selected traits and the information they convey.
• The relationship between sexual signals, performance, and combat outcome is context-dependent.
• Territoriality influences the escalation of conflict and the reliability of sexual signals in Anolis lizards.