Social feeding decisions in horses (Equus caballus)

Abstract

Like many other herbivores, in a natural environment equids feed on rather evenly distributed resources. However, the vegetation in their vast habitats constantly changes. If food is plentiful only little competition occurs over food, and in non-competitive situations domestic horses tend to return to the same feeding site until it is overgrazed. In contrast, they compete over limited food for which the social status of the individuals appears to be important. Especially in ruminants several studies have proved an influence of social organisations, rank, sex and the depletion of feeding sites on the feeding behaviour of individuals. However, it is not yet understood whether and how social aspects affect horses´ feeding decisions. Curiosity about the influence of social rank on the horses´ feeding decisions between two, equally with high-quality surplus food filled buckets placed in different social feeding conditions, led us to create the test below. The observer horses were alternately tested with a dominant and a subordinate demonstrator placed in one of three different positions. We conclude that domestic horses use social cognition and strategic decision making in order to decide where to feed in a social feeding situation. When possible they tend to return to the same, continuously supplied feeding site and switch to an "avoidance tendency" in the presence of dominant horses or when another horse is already feeding there. Thus, the social rank and the position of conspecifics affect the feeding strategy of horses.

The effects of age, rank and neophobia on social learning in horses

“…This would carry much lower time and effort costs than learning a specific feeding behaviour. However, rank was not a significant factor in this study, and horses have not been shown to use conspecifics as reference points when feeding on unlimited resources (Krueger and Flauger 2008),although it is not yet known whether rank is a factor when resources are limited.…”

Dominance rank is associated with body condition in outdoor-living domestic horses (Equus caballus)

“…Individual animals within a group react and behave differently in any given situation, pursuing the best social strategy with relation to other herd members ( Maynard-Smith and Parker, 1976; Krüger and Flauger, 2008 ). Thus different individuals may derive different costs and benefits from group membership ( Alexander, 1974 ).…”

Interindividual variability in feeding station behavior in cattle: A preliminary study

“…1998a). Krüger and Flauger (2008) have reported that horses avoid feeding in a site where another horse is already feeding. Barroso et al.…”

“…An animal may graze a location longer if the surrounding ones are not free, or it may be driven out of a location by a dominant animal (Roguet et al 1998a). Krüger and Flauger (2008) have reported that horses avoid feeding in a site where another horse is already feeding. Barroso et al (2000) have observed that diet selection (consumption of shrubs and forbs) by individual goats in a flock was influenced by their position in the social hierarchy.…”