Preliminary findings in the rolling behavior of Mules (Equus caballus x Equus asinus)

Abstract

In order to investigate and create an ethogram of the rolling behavior of mules (Equus caballus × Equus asinus) in comparison to that of horses (Equus caballus), we observed a domestic free-range, mixed group of 17 horses and 11 mules for two consecutive days (12 h/day), filming all the rolling events. From these footages, we were able to register the occurrence of specific behaviors that characterize the rolling: sniffing the ground prior to lie down; tail swishing; resting in recumbence; scratching and shaking. Moreover, we also observed two social dimensions that are possibly involved with the rolling behavior: 1) Social facilitation - once an animal started to roll, others in the group copied its behavior and 2) Demarcation - animals tended to return to roll in the same dust patches. In this equine group, mules rolled more frequently than horses and also exhibited more of the specific behaviors tail swishing, resting and scratching. Moreover, in the rolling events exhibited by the mules, the social facilitation and demarcation occurred more than in the horses. As a preliminary study, we pointed some important differences between the rolling behavior of horses and mules. Considering the lack of knowledge in this regards such findings could be useful to spread ideas for future studies concerning the mules behavior and to improve the welfare conditions of these animals.