Personality of equids: Donkeys and draught horses behave differently in fear and tactile sensitivity tests

Abstract

Horses and donkeys are used for agriculture, leisure, urban services and therapy. Although these two species obviously behave differently, it is important to measure their behavioural specificity when tested in the same situations and to highlight the existence of some personality dimensions. During 104 breeding shows in France, personality tests validated for horses as measuring fearfulness and tactile sensitivity dimensions were applied to 1-year-old equids: 242 donkeys and 924 draught horses. In fear tests, compared to draught horses, donkeys in-hand moved less during height measurement ( P< 0.0001), walked less rapidly around a novel object (P< 0.015) and refused to move forward more often in front of a novel surface (P< 0.0001). During most tests, donkeys presented less tense posture and less evasive behaviours (P< 0.015). However, during suddenness tests, donkeys in-hand fled similarly to horses. Free in an open field with grass, donkeys walked as much as horses and grazed less (P< 0.0001). Finally, donkeys reacted more to filaments measuring tactile sensitivity (P< 0.0001). These results were often modulated by sex in horses with more reactions in males, and to a lesser degree in donkeys but with more reactions in females. Correlation and principal component analyses (PCA) of these individual characteristics within each species revealed stability of behaviours across fearful situations. In addition, PCA factor loadings revealed concordance between species (inter-factors 1: Kendall Tau = 0.33, P=0.021, inter-factors 2: Kendall Tau = 0.36, P=0.012). This suggested that the two species have similarities in their personality structure. In conclusion, young donkeys behave differently to young draught horses toward static novelties and tactile stimulation, but similarly when confronted with a visual surprise or free in an open field. However, there is probably an underlying common personality structure in the two species. For fearfulness to be considered as a personality dimension in donkeys, further studies are required to demonstrate its stability over time. These results have implications for animal welfare, because the fact that donkeys do not move does not mean that they are not afraid. Physiological measures and finer behavioural observations are required to characterise more precisely fear in donkeys. There are also implications for the safety of inexperienced people unaware of the danger of certain situations, particularly when equids considered to be placid are involved.