One of Thelwell's iconic illustrations of the Shetland Pony

How does one of the smallest breeds of the Equine family communicate? What brings about their social interaction?


Shetland ponies, famously depicted in Thelwell's humorous cartoons of little girls and their ponies, is amongst the smallest breeds of all horses (Equus ferus caballus). It developed in the highland country, Shetland Isles. As a breed, they were able to maintain their original characteristics because they were not heavily crossed with other horses due to the isolation of the Shetland Islands and the inhabitant’s preferences. 

Their physical traits include their miniature size of a maximum height of 42 inches, strength and robustness, mainly due to their development in harsh conditions, which made them popular for their changing role in the service of mankind. Their docile nature and intelligence are also appealing characteristics which make them ideally suited for children and also as guide horses.

Wild and Domestic horses

Dr.McGreevy from the University of Sydney, thinks, that it is crucially important to look at feral horse behaviour to understand better the behaviour of domesticated and stabled horses since comparisons between the two may shed light on normal and abnormal types of behaviour.

Presently, the closest approximation to wild or feral horses is those that are free ranging like Mustangs, New Forest ponies or Assateague ponies, since the last wild horses, the Przewalski , has been domesticated in the 1950’s to prevent them from going extinct. Nonetheless, behaviour which is not normally seen in feral horses, is considered abnormal behaviour in domestic horses.

Moreover, though many domestic horses have a chance to socialise with other individuals within their own species, others are not kept within a herd or constantly out at pasture, as their wild ancestors. So some may argue that due to equine management, only some of the behaviour of domestic horses reflect their natural state.

In addition, the behaviour of each individual is a result of an evolutionary adaptation to their environment. So each behaviour observed in an animal, increases the chances of its survival in that specific niche and within that particular community. Understanding the natural environment of horses is essential as it is closely linked with the horses behaviour since the survival and reproduction rate are greatly influenced according to the environment. So it seems that these innate motivations of wild ancestors have been passed on to the present generations of domestic horses without being changed. 

Understanding Social Behaviour

The increasing interest in horse's social behaviour research is enabling us to understand why a horse behaves the way it does.

As other social animals, horses need to communicate. They have developed a social hierarchy in which older and larger horses dominate. This way, every horse has a position in the herd so that tension between individuals is kept minimal and cohesion between group members is increased. For example, less dominant horses will move out of the way and show respect by backing off, when the dominant horses are around.

However, when horses are socially interacting, social cohesion is usually more common than aggressive behaviour. This type of behaviour has developed this way so that individuals would not spend much time and energy engaging in fighting behaviour to guard their resources. So they have highly developed social skills making them very communicative animals which are motivated to cooperate rather than dominate.  Because of this, horses usually make some kind of visual signals as warning before engaging in attacks. These signals intensify slowly and usually initiate by a change in the ear position. In addition, since their natural environment is open spaces, they have not developed a highly complex vocalisation so their main way of communicating with each other is through body language.  So, the general body posture and the way ears, tail, face and neck are aligned, tells you alot about a horse. 

Grooming and Play Behaviour

Some domestic horses in Montrose were observed and two main types of social interactions, play and grooming behaviour, were the most evident.                                                                                                         

Watch: Social Interaction amongst 3 Shetland Ponies 

Rolling Behaviour is especially common amongst horses living under natural herd conditions. This behaviour serves various purposes; pleasure, self-maintenance, increasing comfort by scratching, aiding in shedding, restoring maximum insulation properties especially when it is raining, helping repel biting insects, maintaining flexibility by stretching all the muscles in the spine, neck, barrel, flanks, and buttocks  and in social and grooming interactions.

 

Rolling behaviour in a random Shetland
pony in Sweden

In both wild and domestic horses, something like a smell or presence of water or absence of debris, in a particular area, known as the common rolling area, stimulates this behaviour.  Scientists think that this type of behaviour can also be socially facilitated. Similar to yawning in people, rolling of one horse seems to stimulate rolling of a herd mate or a relative. This is very commonly seen in young foals. So it seems to have some sort of mimicry amongst individuals of the same herd.

Moreover, it is a part of a ritualised inter-male behaviour which is very noticeable in bachelor bands.  Inter-male events occur between pairs or small groups of males which investigate each other, posture, stamp and defecate in a stylised manner, near a rolling site and include ‘’taking turns’’ rolling in a fixed order, either before or after the aggressive tiffs. The most dominant male goes last in order. Once the order is established, the order is repeated in the same way, day after day. If there are two groups with different members of different orders that pass at the rolling site at the same time, the dominant group always gets to use it first. If they are similarly dominant, the two most dominant horses from each group, have a ‘’conversation’’ over the rolling site and who wins gets the rolling site.

A fascinating ‘‘engineering skill’’ takes place in these sites. Horses create some sort of dust bowl by repeated rolling in the same spot which helps to remove the vegetation and erodes the surface, forming a shallow bowl. After some time, the bowl becomes very compacted base lined and fine powdery soil accumulates. It also becomes ''oiled’’ with body residues. There is an increase in rolling behaviour in summer as it gets hotter and drier. In this way, the bowl becomes more deep and compact. When it rains, the dust bowls gather water and become temporary watering sites. This type of behaviour proves to be a great example of an adaptive behaviour-environment interaction that does not require any cognitive thought in horses. So this rolling behaviour has evolved in serving survival needs whilst satisfying other short-term purposes. 

Two of the Shetland ponies in Montrose grooming each other

Allogrooming is also an observed behaviour amongst the three horses in Montrose. It is an activity in which two individuals clean or maintain each other's appearance. So it is a mutual type of behaviour which may build new relationships or reinforce an existing one. Studies have shown that this behaviour reduces heart rate so it is important for reduction in stress.

Mares lick their foals after they have given birth as part of the bonding process. In this way, the foals associates this type of behaviour with bonding behaviour and continues to do it later in life to bond with other horses, not necessarily relatives.  Usually one horse initiates the mutual grooming session and their partner is usually delighted to cooperate by nibbling in return. 


This type of behaviour have evolved to be a resource that is exchanged for other resources. For example, one horse gives grooming favours and in return he is allowed to mate with the grooming partner. Usually food and sex are two common exchanged resources. Grooming behaviour can be followed by play. 

Watch: Grooming followed by play behaviour in a mutual relationship amongst the Montrose Shetland Ponies 

Several studies have proven that horses search for partners which they will life long bond with. Play behaviour is one of the ways which enhances and strengthens this bond.  Usually, the pair bonded horses seek each other out as preferred play partners. Most of the times, one horse initiates the game, and the rest of the horses pick up the signal and joins in.

Ethologists suggest that safety and weather conditions cause the horse’s motivations to initiate play. Since they are prey animals, safety is a priority that has to be considered at all times as any distractions may lead to mortality. Ideal conditions need to also be present since otherwise it might affect their sensory perception of their environment. Therefore, rain or wind may compromise vision, smelling and hearing which may put them in a dangerous position if a predator is approaching.

Solitary play may aid foals in developing appropriate muscle movement to help them deal with what they might encounter later on. So this type of behaviour may serve both as practice and exercise. The mare usually allows the foal to concentrate on solitary business of perfect locomotion whilst she provides food and protection. The foal does this type of play by running, hopping, kicking, jumping, and skipping around his mother often in circular patterns. At this stage, it is a major component in enhancing blood supply to different part of the foal’s body and this continues until vascularisation is achieved and when this is done, the foal can test his muscles with other youngsters in the herd.

Engaging in play behaviour has evolved in a way in which it simulates a fleeing response from a predator, especially when they choose a ''chase and charge’’ play pattern where the whole herd runs flat out together in specific directions.

An accurate translation within the environment the horse is situated in, is needed for a better understanding of horses social behaviour. Though we may understand many interactions that goes on amongst the Equine Family, there are still much more to be learnt from these majestic creatures. 

Reference

Odberg, F.O., 2005. The evolution of schooling principles and their influence on the horse’s welfare. In: P. McGreevy, A. McLean, N.Waran, D. Goodwin, A. Warren-Smith (Eds.), Proceedings of the 1^st International Equitation Science Symposium, Broadford, Victoria, Post-Graduate Foundation in Veterinary Science, Sydney, pp. 4–9.

Feh, C. and de Mazieres, J. (1993). Grooming at a preferred site reduces heart rate in horses. Anim. Behav. 46, 1191-1194.

Lieberman, D.A., 1990. Learning: Behaviour and Cognition. Wadsworth Publishing Co., Belmont, CA

McGreevy, P.D., 2004. Equine Behavior: A Guide for Veterinarians and Equine Scientists. W.B. Saunders, London.

Skipper, L., 1999. Inside Your Horse’s Mind: A Study of Equine Intelligence and Human Prejudice. J.A. Allen & Co., London