A behaviour by which a male gull threatens a rival that persists in an attempt to invade its nesting site. Males arrive at the nesting ground before females. Having taken up position, the male repeatedly utters a loud call, known as the long call. If another male then approaches, the bird raises its head, holding its bill in a position from where it can strike downward. This is the upright display. If this fails and the rival persists, the bird holds its body parallel to the ground with its bill forward, pointing directly at its rival. This is the forward display and the bird will often follow it with a charge and attempt to stab its rival and strike it with a wing.
Subjects: Zoology and Animal Sciences.