Social Behaviour of Horses in Response to Vocalisations of Predators

SIMPLE SUMMARY: Animal social strategies are of importance when avoiding predation. Since horses are the least hunted among all farm animal species, we suppose that the alert reaction to a predator’s vocalisation, followed by anti-predator social behaviour, still exists in domestic horses. Recorded vocalisations of three different predators (grey wolf, Arabian leopard and golden jackal) were played to 20 horses of two horse breeds—namely, Konik polski and Arabian. Social responses and tactics in antipredator behaviour differed between the breeds and between predators. Koniks exposed to vocalisations of a howling wolf resulted in tight groupings, while Arabians exposed to the growling of a leopard responded with linear group formation. The behaviour of studied horses, expressed by alertness and defensive formations, indicates existence of the social anti-predator behavior, which in turn may explain the low rates of horses falling prey to predators as compared with other farm animal species. ABSTRACT: We tested the hypothesis that social defensive responses to the vocalisation of a predator still exist in horses. The recordings of a grey wolf, an Arabian leopard and a golden jackal were played to 20 Konik polski and Arabian mares. Durations of grazing, standing still, standing alert and the number of steps in walk and trot/canter were measured. In one-minute scans, the distances of the focal horse from the reference horse (DIST-RH) and from the nearest loudspeaker (DIST-LS) were approximated. The vocalisation of a leopard aroused the Arabians more than the Koniks (less grazing, stand-still and walk, more stand-alert and trotting/cantering). Koniks showed more relaxed behaviours to the leopard vocalisation (more grazing, stand-still and walk), but high alertness to the wolf playback (stand-alert, trotting/cantering). Spatial formation of the herd of Koniks showed tight grouping (lower DIST-RH) and maintaining distance from the potential threat (DIST-LS) in response to the wolf howling, while the Arabians approached the loudspeakers in linear herd formation when the leopard growls were played. Adult horses responded to potential predation by changing spatial group formations. This ability to apply a social strategy may be one of the explanations for the least number of horses among all hunted farm animal species.