Cooccurrence of Yawning and Stereotypic Behaviour in Horses (Equus caballus)

Table 1

Type (oral/motor), name, and description of stereotypic behaviours recorded, adapted from [18, 25].

Type	Name	Description
Oral	Cribbing	The horse grasps a fixed object with its incisors, pulls back, and draws air into its oesophagus while emitting a characteristic pharyngeal grunt.
	Lip play	The horse moves its upper lip up and down without making contact with an object, or the horse smacks its lips together.
	Tongue play	The horse sticks out its tongue and twists it in the air.
	Lip or teeth rubbing	The horse rubs its upper lip or its upper teeth repetitively against the box wall.
Motor	Head shaking and nodding	The horse bobs repetitively its head up and down or tosses its head in recurrent and sudden bouts.
	Weaving	The horse sways laterally, moving its head, neck, forequarters, and sometimes hindquarters.