Table 1.

Description of circumstances in which images where obtained from videos.

Situation	Description
Pre-agonistic	Focal animal has entered the contest arena and has not yet made contact with the opponent. No aggression has yet occurred.
Aggression	Focal animal initiates an aggressive act (push or bite) or retaliates to an aggressive act. In the case of biting, the frame just before or after the bite was selected so that the mouth was not fully opened.
Retreat	Focal animal withdraws from aggressive act, either by showing a head-tilt, turning the body 180° away from the attacker, or by fleeing from the attacker.