Líffræðifélag Íslands
Líffræðiráðstefnan 2015

Erindi/veggspjald / Talk/poster E6

On the determinants of social behavior in adult horses: the importance of individual and group characteristics

Hrefna Sigurjónsdóttir and Martine Hausberger

Háskóli Íslands, University of Rennes, Frakklandi

Kynnir / Presenter: Hrefna Sigurjónsdóttir

Tengiliður / Corresponding author: Hrefna Sigurjónsdóttir (hrefnas@hi.is)

Results from studies of social interactions (aggressive, submissive, allo grooming, play) in 19 groups of pastured Icelandic horses (330 horses in total) are used in multivariate analyses (PCA and GLM). The composition of the groups and conditions varied with respect to the variables: stability, group size, proportions of geldings/ mares/ sub adults, presence of stallions (6 groups) and more. Both individual and group characteristics determined the type of social interactions performed by each horse. Geldings were both more aggressive and submissive than either mares or stallions. Adult play was almost restricted to geldings. The higher the ratio of sub adult to adults the higher the rate of aggression, play and allo grooming. Group stability was highly influential on the frequency of the different social interactions. Both aggression and submission decreased with increasing stability, while allo grooming was more frequent in unstable groups and play in nearly stable groups. Such effect of stability was not observed in the bands with a stallion. One major finding was that the frequency of social interactions, especially agonistic interactions, was much lower in the family groups (bands) than in other groups. These results are important in terms of understanding the determinism of social interactions. Their relevance for horse group management is also clear.