Abstract: Intraspecific aggression constitutes a significant proportion of conspecific behaviours among many mammal species. Agonistic interactions among male bottlenose dolphins (Tursiops truncatus) have been documented in several different regions, including escalated aggression involving coalitions comprised of several males. However, despite many hours of direct observation most of these encounters are evidenced by minor injuries and often, physical wounds are not visible. Herein, we describe a unique encounter involving a long-term male alliance competing with a ‘solo’ male that resulted in the temporary loss of consciousness of the lone male following repeated physical blows to his head region. This observation supports the increased fitness experienced by males in alliances and illustrates the potential severity of aggressive interactions among adult bottlenose dolphins.

Key Words: AGGRESSION; UNCONSCIOUS; SOCIAL STRUCTURE; TURSIOPS TRUNCATUS; ALLIANCES; DOLPHIN

Document Type: Research article