ADVICE SHEET 18
Social Structure of The Horse
Written by and Copyright: Debbie Busby BSc (Hons), MBPsS
Group Structure
The horse is a social species
They choose to live in social groups where there are consistent rules governing relationships and interactions, and they engage in the three Cs of a stable, social society:
- Communication
- Co-ordination
- Cohesion
This means they must be able to recognise and remember fellow group members, co-ordinate activities among each other and perform affiliative, social behaviours to keep the group bonded and together. As a prey animal, vision is the primary sense on which the horse relies to prepare itself for flight. As well as using visual signals to communicate with other horses, the horse uses auditory, chemical (smell and taste) and tactile signals.
Social Structure
Horses live in co-operative family groups
In free-ranging wild horses, stable social herds take the form of family groups, where one stallion lives with several mares and their offspring, and all-male bachelor bands (sometimes a sub-group of the main herd) of adult males who have left the family group but who do not have their own harem. There are strong family bonds within the group, especially between mares and their foals. Fillies generally stay in the herd in which they were born, whilst colts form their bachelor groups at about age two. The groups exist because of the effort made by its members to stay together, so we can say that horse are affi liative, and practice a co-operative social system known as “follower-ship”.
Horses bond in pairs for safety Pair bonding is an important and signifi cant aspect of herd life. Horses choose a preferred social partner, typically (but not necessarily) one of similar age, sex and size, and, if permitted, the friendship is established for life. Pair bonds allow each other into their fl ight zone and into their personal space to engage in socially facilitative behaviour such as mutual grooming and play. The primary biological and evolutionary purpose of pair-bonding is protection
Size matters
The numbers within a group can be as small as three, but most groups naturally consist of not more than about twenty individuals, and social circles within a large group are often less than ten in number. When keeping horses in captivity it is advisable to consider the space we have available when deciding what number of horses to keep – if space and other valuable resources are restricted, a group of more than about ten may not be able to organise themselves suitably, leading to aggressive encounters between individuals.
The alpha stallion protects and co-ordinates The alpha stallion has an important role in the maintenance of group cohesion. He acts as the coordinator of the herd, keeping the females and their offspring together and following behind the group when it moves. Apart from when his mares are in season, he interacts freely with other stallions in the bachelor band. He is the primary reproducer with the adult mares, and acts with the other bachelor stallions to protect the mares and foals. The alpha stallion leaves specifi c dung piles (stud piles) within the home range.
The alpha mare is the herd leader Usually the oldest mare, with the genetic advantage of being the daughter or granddaughter of other alpha mares, she has knowledge of the routes and terrain the herd travels, and its potential hazards, and the location and quality of resources. She will make important decisions that affect the survival of the whole herd, such as when it is safe to move on, or when it is safe to drink.
Horses avoid aggression The cohesive nature of the social group means that horses avoid aggressive encounters wherever possible, because it uses up valuable energy, it presents risks in terms of health and injury, and it weakens the affi liative cohesion of the group. Aggression always indicates instability in a relationship. In a well-established relationship, the subordinate individual will defer to or avoid the dominant one. Because of the need to avoid aggression and its risks, there is a wide range of escalating threats before physical contact is made. Aggression between groups of horses, such as that often seen on yards or grazing where individual group members change or are temporarily removed (e.g. when not turned out, or at shows), is an indicator that relationships between group members or individual horses are not fully established, or have not been given the opportunity to become stable.
Wild groups of horses occupying vast expanses of land may live together as very large herds, but this is where resources are so widely available without the need to compete for them. Each unit within the larger herd keeps itself separate, while interacting positively with the other groups. Each herd has a home range that can overlap with other herds, and separate herds often band together and share plentiful resources. When resources become scarce, each herd returns to its own home range and can become more territorial as competition for resources increases – this is the situation for most captive horses where their home range is artifi cially restricted and the resources within that range are valuable and worthy of holding