Herd Behaviour Documentation 2015: Part 1

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Introduction

Studies and research on equine herd behaviour and social behaviour are abundant, with majority of them agreeing on the theory and in principle saying the same thing. It is known that horses are social animals and in the wild they live in herds that have their own complex and dynamic social structures and hierarchies. Being prey animals whose primary aim is survival, both as an individual and as a species, living in a herd satisfies this primary aim. It is this basic instinct that has created this social need and communicative capability in horses today.

If you’ve ever had the privilege of sitting among a group of horses in a paddock or field, and just observing how they interact with each another, you’d appreciate the complexities of their communication systems. It begins with the subtlest of cues, easy to miss for us humans who are used to louder and more obvious ways of communicating. A slight flick of a tail from one horse will send a clear message to another. Horses do increase the intensity of their communication when needed; however, it always starts with that first subtle cue.

Most social and herd behaviour studies are fairly extensive, and have identified the various ways in which horses communicate, how they define their space and territory, how they fight, defend themselves, or attack. The sounds a horse makes have been classified, and their body language has been thoroughly studied. However, new research is constantly challenging some original theories around social structures and herd behaviour. This just shows you how complex and magnificent these animals are, and that the need to study their behaviour is still very relevant.

Background

The herd used for this particular documentation is stabled at a private stable yard in Pretoria East, and consists of 24 horses (at the time of the documentation), all geldings of varying ages, breeds, sizes, disciplines, uses and conditions. The herd is fairly established in their social structures as some horses have been together for many years, however there have also been a number of recent additions to the herd that have subsequently challenged pre-existing hierarchies resulting in a very socially dynamic herd.

The aim of this documentation was two-fold – firstly to observe and record specific aspects of existing theory around herd behaviour and normal equine behaviour, and identify whether these aspects apply to a South African environment, or possibly differ in some way. There is very little research that currently exists around social and herd behaviour in South African horses therefore it was important to identify whether any differentiators exist as this would then allow for further research and exploration.  It was also important to identify potential behaviours in this herd that would support some of the newer research on herd behaviour and social structures. The second aim is to document how a herd reacts to a new environment, especially investigative and exploratory behaviour, as well as social interactions during this phase of exploration and investigation.

The unique aspect of this herd was that they were being relocated to a new paddock, one they were not familiar with and had very limited exposure to previously, if any at all. This provided the unique opportunity to observe a herd’s behaviour in a new environment.

The study was documented using video, as well as visual observation over a period of seven hours from when the horses entered the new paddock, to just before they were taken back to their stables. All footage is from the day of the relocation only, and does not include any later observations or footage of the herd.

Part 1 documents this first phase from the perimeter walk to the release. In later videos, further investigative behaviour and social interactions will be explored.

Part 1

Perimeter walk

The move was scheduled early in the morning on Saturday, 2 May 2015. None of the horses had been released from their stables before the move. The reason for this was that a herd of mares had already been moved to the geldings’ previous paddock. As a safety precaution, each horse was to be led on a halter into the paddock and walked around the perimeter before being released. This was done to avoid serious injury to the horses as three sides of the paddock are bordered by electrical fencing only. If the horses were just released without prior exposure to the fence line, we could have run the risk of the horses running into the electric fence as it’s not easy for them to distinguish the wires among the backdrop of tall grass and trees.

It was interesting to observe how each horse reacted to the new environment during the perimeter walk. Some were very calm, and walked placidly alongside their handlers, casually observing the new surroundings. After a few rounds of the paddock, they settled to graze. Others were skittish, difficult to handle, and you could see by their body language that they were very alert and tense. They were very sensitive to any sounds and objects around them. One horse managed to get loose and ran around for a while before being caught again. Once all the horses had walked around the perimeter a few times, they were led to the centre of the paddock to graze alongside their handlers.

The different initial reactions were quite interesting, and spoke strongly to the different temperaments and personalities of the horses. Vocalisation was also prominent during this phase, there were a few whinnies as the horses were calling to each other and seeking security. Snorts were frequently observed in the more skittish horses in reaction to the unfamiliar environment and situation.

The release 

Once all the horses had gathered in the middle of the paddock, the handlers were instructed to remove the halters and leave the area as quickly as possible to allow the horses to explore the environment on their own.

The assumption during this phase was that the horses would all begin to run as their natural flight response kicked in, in reaction to the unfamiliar environment and situation. The flight response is a natural, reflex reaction for a horse when in an unfamiliar or threatening situation. It can also be a bit of a domino effect, as one horse runs, the rest follows, and confirms the theory that the tendency exists for horses to mimic each other in a group situation.

As soon as the halters were removed and the people started to move away, the horses each began to move around. Some immediately started running, others stood for a short period then joined the running groups. One horse in particular you’ll notice at around 00:48 in the video clip remains quite calm and is still grazing as his handler starts to move off. He looks up and notices the commotion around him, but his body language is still calm. A few seconds pass and you can see the change in body language. Head goes up higher, the body tenses, and he begins to seek out the horses closest to him that he can follow, as his flight response is actioned. This type of observation confirms allelomimetic (mimic) behaviour, which is a normal inherited response specifically in group situations, and also shows that the flight reaction does not occur at the same time or with the same intensity in all the horses.

You could easily observe the signs in body language that the horses were alert, excited, and very aware of their surroundings. Tails up, ears forward, nostrils flared, heads up. The same is true for when they began to relax, the change in body language was very clear. As the instinct to survive is an inherited behaviour, meaning it is part of their natural make-up as a species, behaviours that are performed with the aim of surviving are therefore reflex behaviours and occur automatically, as was observed when looking at the physiological responses and body language during this initial release into the paddock.

Their movement and grouping was very interesting to observe. Initially it was chaotic, with little structure. Horses were running off in different directions. A small portion of horses moved towards the fence line and remained standing there rather than respond with flight. It was interesting to observe that the herd didn’t act as one cohesive group, but split off into smaller groups, and some individually. What was seen however, is that the main group was fairly large and consisted of majority of the horses. The smaller groups and individuals were a small portion of the total group. This could speak to hierarchical structures within the herd, though it must be noted that human interference could also have had an influence in this case. Most of the owners were still observing the herd from the fence, which could have had an influence on the behaviour of the horses that broke away from the main group to seek safety with their human handlers at the fence. This indicates the effect of domestication on normal horse behaviour, and certainly leaves room for further study and research.

As the flight response is a natural reflex response to fear, threats and danger, the initial movement is unstructured and reflexive, with the aim just being to get away to safety. However, herd instinct is also strong, and the need to survive is aided by numbers, so you will notice how quickly large groups form while the flight reaction is ongoing. Two main groups in particular form early on during the flight response and the movements automatically become more structured as herd leaders come into play and information processing takes over from the initial reflex flight response.

The direction of the movement is also interesting. At 1:16 in the video you can see a group running along the perimeter of the paddock (top right corner of the video). There is another group, off-camera, running along the perimeter on the opposite end. The two groups join up at 1:21 in the centre of the paddock, which results in some conflict of space and panic, nicely displaying agonistic (aggressive) behaviour. After a short stop, the groups change course again and continue running as one large group together.

There seems to be a pattern in the way they move through the environment. It begins with the flight response, which is a reflex reaction at first and unstructured, but then quickly becomes structured as herd instinct takes over and they begin to make decisions and process information from the environment and each other. They move closely together in a group, and don’t seem to be trying to outrun each other, but rather take direction from the leader who is normally the horse at the front of the group that guides the direction of the movement. They run along the perimeter corner to corner, almost in a figure-8 pattern, crossing down through the centre to the next corner. There is a definite but brief pause in the corners, followed by a change in direction before collectively running off again in the same structured manner. This similar pattern is repeated throughout the flight response and subsequent early investigation.

This pattern that has been observed highlights a number of aspects: (1) is that the ‘pause’ is used as a way of gathering information from the environment, ascertaining whether it is safe or not, and if not, getting their bearings and deciding which direction to go in again. As this pause always occurs in a corner, or an area where they are bordered by fencing, never in the open. (2) It indicates that they seek an area that seems safe and more protected to make these decisions and process information, and (3), once the herd begins moving again, it is always in the opposite direction, but sticking to the same pattern.

Based on these three observations, the assumption is that the ‘pause’ is indicative of an early investigation phase, allowing the horses to briefly process information from the environment (bearings, direction, safe or not etc.) and make a decision based on this. The fact that all of this is decided in a few seconds shows the amazing communication and sensory systems that these animals have. If the environment is not deemed as safe yet, they will continue moving and investigating until it becomes safe, or a safe zone is identified.

Another very interesting observation is that the first horse to take off again after the pauses, which indicates that he is the leader for the moment, is not always the same horse. You will notice throughout the video that each time there is a pause, then a change in direction, there is also a different leader. It alternates between dark and light horses, and at times you will observe the pinto horse leading. This observation supports the latest research by behaviourists indicating that there isn’t one primary alpha as leader of a herd, but rather multiple leaders that change multiple times throughout the day depending on the circumstances. If a horse has followers, then they are the leader at that moment. As soon as the followers are lost, the leadership status is lost as well. This new research links leadership to the horses that are more social and extroverted, rather than the previously assumed characteristics of dominance and aggression that were used to classify the alpha horse.

The whole group eventually comes to a final stop, collecting at the top of the paddock close to an area dense with trees. This area was used multiple times as the ‘pause’ area during the flight and initial investigatory phase, and was then chosen as the final area to settle in. This supports the assumption of the ‘pause’ being allocated time for investigation and decision-making, specifically around the safety of an environment. This also supports existing theory that horses use investigation partly as a means of identifying whether an environment is safe or not.

After this final stop, the main flight and initial investigation was over, lasting approximately fifteen minutes in total. The second phase of investigation then began, as the horses broke off into smaller groups and began exploring the environment for food and water.

Once an environment is deemed ‘safe’ from threats, food, water and shelter are the next needs that need to be satisfied. During this phase the horses began to spread apart more quickly so that the smaller groups and pairs became more evident.

There was little aggressive behaviour observed during this initial flight phase, apart from a few brief instances of panic and confusion resulting in fear-based agonistic behaviour, but you could see that the primary instinct was for survival. Their communication throughout these few minutes of flight was astounding.

Below is an overview of the observations and assumptions that were identified:

  • Safety is the primary need that must be satisfied, and the flight reaction, while being a natural instinctive response to danger, is also the first step to determining a safe zone as part of early investigatory behaviour.
  • The flight reaction is not the same for every horse and is most likely influenced by temperament, personality, and social status of the horse, as well as how the individual horse is processing information from the environment.
  • Initially the flight reaction is purely reflex, however information processing and decision making comes into play fairly quickly, changing the nature of the flight reaction from reflex to voluntary investigation.
  • Domestication has certainly had a large impact on this herd’s natural behaviour, as some horses chose to remain close to the people rather than join the herd. This also speaks to their social statuses within the herd, and how they are ranked. It does require further study and research to gain more clarity.
  • A definite pattern has been observed following a flight response, linked closely to early investigatory behaviour, and the decision-making process around safety.
  • This study supports the new research on social structures and herd leaders, indicating multiple herd leaders chosen for their social qualities rather than dominance.
  • Safety is the primary need that has to be satisfied, after which food, water and shelter become the main needs.
  • Based on these observations, further study and research is required to determine whether the assumptions made are accurate, and to further explore herd and social behaviour.

The next phases of investigation behaviour and social behaviour will be explored in upcoming videos.

Thank you for taking the time to read Part 1 of this study and watch the video!

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Thank you to the Stable owners, team and stablers for allowing this documentation to take place. (Names have not been mentioned in order to maintain privacy) All safety precautions were taken to ensure that no animals or people were injured during the study, and as little human interference as possible was maintained throughout the documentation in order to gain as clear findings as possible of normal horse behaviour.