Social relationships in a herd of Sorraia horses Part I. Correlates of social dominance and contexts of aggression.

The research paper is an examination of social dominance and the use of aggression in a herd of Sorraia horses. The study found that the dominance hierarchy among the horses was mostly determined by age and aggressiveness.

Study Overview

• The research was conducted on a herd of Sorraia horses, which consisted of ten adult mares between the ages of 5-18 years and a stallion introduced for breeding purposes.
• The researchers primarily focused on observing the correlating factors that influenced the dominance rank among the mares, and the reasons behind the instances of aggression within the herd.

Dominance Rank and Aggression

• The study found that the dominance hierarchy among the mares was significantly linear and stable, even after the introduction of the stallion.
• The rank of dominance was positively correlated with the age of the horse and the total aggressiveness the horse displayed.
• An interesting observation was that higher-ranking mares had a lesser frequency and intensity of aggressive interactions or attacks compared to lower-ranking mares.
• However, it was noted that higher-ranking horses were not necessarily more likely to get submission from their subordinates over lower-ranking horses.
• Even mares that had close ranks or unclear dominance standings were not more aggressive towards each other. Aggression, concluded the researchers, was used more to regulate space rather than to get food or reinforce dominance.

Contexts of Aggression and Dominance

• The reasons for aggression were found to be linked to the social rank of the mares.
• The research paper suggests that dominance relationships established on the basis of age served as a conventional criterion in the herd of horses.
• This appeared to decrease the overall aggressiveness in the herd, acting as a way to reduce tension and avoid fights where the potential costs of aggression would likely exceed the benefits.

Conclusion

• The study provides an insightful look into the social structure and behaviors seen in a herd of Sorraia horses.
• The dominance hierarchy within the herd was directly related to age and aggressive behaviors, and aggression seemed to be a means of regulating space rather than obtaining food or emphasizing dominance.
• The conclusions drawn could potentially be relevant for future studies of social behavior in similar animals or even diverse populations, in an effort to understand dominance relationships and the functions of aggression.