Limb preferences and lateralization of aggression, reactivity and vigilance in feral horses, Equus caballus

► Feral horses show left-side biases in agonistic responses, reactivity and vigilance. ► Leftwards bias was stronger in behaviour involving higher aggression and reactivity. ► No population bias of forelimb preference was found in the feral horses. ► Immature horses showed stronger limb preferences than adults. ► Limb preference was associated with elevated attention to the environment.