Cooccurrence of Yawning and Stereotypic Behaviour in Horses (Equus caballus)
Figure 4
Yawning frequency (per minute) (a) and stereotypic behaviour frequency (per minute, pooled data for oral and motor stereotypic behaviours) (b) in riding school horses. Horses yawned and displayed stereotypic behaviours more often half an hour before meals (i.e., 6.30–7.30 a.m., 11.30–12.00 a.m., or 5.30–6.00 p.m.) than during either the morning (9–11 a.m.) or the afternoon (2–5 p.m.) periods. Friedman and Wilcoxon tests, ***.
