Animal Behaviour © Authors Photography
A review of behavioural research
Equus Caballus
T
he horse, (Equus Caballus) has been in existence for millions of years and has changed greatly through evolution, which has had an effect on the horse’s physical characteristics and behaviour through natural selection. Fossils found over the years indicate how the horse gradually adapted to the changes in the environment. Some of the evolutionary developments that took place relate to teeth changing, adapting to the changing diet, improved distance between the eyes which increased the lateral vision allowing them to watch for predators when eating, a longer neck improving range of vision, longer limbs
showing an adaptation for running, changes in the toes developing to a single toe protected by a hoof. Evolutionary pressures affecting the horse © Mattew Mihbacler throughout evolution include To understand how horses teeth changing climate (hotter and evolved, researchers graded the of molars compared to drier), decreasing forests and sharpness fossils. reducing habitat and tougher grassers formed that could Social groups and withstand the harsher behaviour: conditions. Horses have therefore evolved and being utilized to man to become more useful, such as faster and stronger to cope with the man’s work.
Horses are social animals, wild or feral they live in family or bachelor groups. A family group is made up of a single stallion with his harem of mares, juveniles and foals.
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Animal Behaviour © Authors Photography
A band is a group of horses with at least one male and one female that move around together, though multiple stallion bands do exist two or more stallions live in a group of mares, juveniles and foals, but only one stallion is dominant. A group of males is called a bachelor group and males sometimes live alone. Within the band the herd has a structural social unit. Studies show that stallions are neither
dominant nor the most aggressive in feral and domesticated horses. When juveniles reach 2-4years old they move away from the parent’s band and join or form their own band. Horses form a pair bond within the group, they graze and rest together and mutual groom. Pair bonds play a role in social support in difficult conditions. A problem in a domestic environment is that social groups constantly A pair bond.
change so interband relationships are not often settled. Horses have a “flight zone” which is the space around the horse, when something enters this zone it causes the horse to move away. The reaction is genetically fixed and occurs according to an ‘’inborn elicited mechanism’’. The flight distance is species-specific behaviour and it has been documented that wild horses have a bigger zone than the domestic horse. The reaction is known as the flight or fight response, it is a defence strategy which protects the individual horse; it’s also known as a first order homeostatic behaviour. Because horses are a prey species they tend to use flight rather than fight, the trigger for this behaviour is normally an enemy, frequently referred to as a perceived threat, threat or aversive stimuli. The sympathetic system is involved in the flight/fight response.
© Authors Photography 2
Animal Behaviour Š HowStuffWorks
Figure 1. This diagram shows the process of the flight or flight response.
Š Lisa Pinno
Figure 2. Representation of flight distance
Communication: Horses can show their motivation to behave and interact through vocal communication.
They can share the emotional and physiological state and situation to other horses and humans.
Vocalizations can be split into a number of types, whinnies, nickers, squeals and groans use the larynx and snorts, blows, mouth smacking and incidental sounds are non-voiced sounds. 3
Animal Behaviour
Whinnies last between 0.52.8 seconds and are high in amplitude, the longest and loudest vocalization; and are used as a separation, reeting or distress call. Horses can distinguish others by their unique auditory vocalization when matched with a visual stimulus. Nickers are a low-medium amplitude call ranging from 0.2-1.7 seconds around 100hz. The nature of a nicker differs with the circumstances, one being when the owner if preparing to feed, another during sexual behaviour and also one given to foals by mares. Squeals heard during aggressive interactions, defensive threat greeting also heard in response to pain or during sexual encounters. Groans occur during discomfort such as mare foaling, during mental onflict or undergoing physical effort. Blows last around 0.5 seconds and occur in response to an intruder to alert the herd, also heard during olfactory examinations. Snorts can be heard as an alarm call, during play or exercise.
Interspecific communica- Domestication: tion – Body postures play a
part in communication and organising group activities. Horses are sensitive to changes in body language as they are mainly visual communicators. To alert the herd to danger the horse’s posture is of high tension. Licking and chewing is a submissive behaviour and is shown during work in a round pen. It may be a displacement activity or comfort behaviour. Horses also communicate through using their ears.
Horses have evolved through domestication to adapt to man and the environment. Domestication is a process in which a population of animals becomes adapted to humans and a captive environment, the changes and differences between domestic and wild horses are possibly an outcome of genetic and developmental aspects.
Š Authors Photography
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Animal Behaviour
Figure 3 (Yeon,2012) - Spectrogram of vocalizations. A - Whinny, B - Whinny from seperaton, C - Nicker, D - Squeal by diestrus mare on stallion approach, E - Squeal by estrus mare when stallion approached, F- groan, G - Blow (Alarm), H - Blow (after sniffing), I - Snore, J - Snort. 5
Animal Behaviour
Still the horse remains mentally and physically adapted to life on an open plain, the plasticity in the behaviour allows the horse to make use of other habitats such as the New Forest’s woodlands or Camargue marshlands.
© Authors Photography
Domestication has allowed horses to be provided with shelter, food, protection and veterinary care. The food they intake is controlled by the owner to suit the level of work, natural selection has been replaced by humans for artificial selection, whereas in the wild the horse is a plains dweller which wanders over open spaces, keeping on the move and grazing little and often. Humans see stables as a safe, comfortable bed offering protection, although it goes against the horse’s survival instincts and leads to vulnerability through isolation, restricting sensory input in detected predators and preventing escape.
weight loss, colic, strain on joints and ligaments, reduced condition, uneven muscular development and fatigue.
Crib biting is the most common stereotype, according to a study by McGreevy, 2.4-8.3% in Europe and Canada display this behaviour and a study Through domestication by Albright 4.4% in the United States. The horse by putting horses in grasps a fixed horizontal an unnatural environobject (fence, stable door ment they can learn etc) with incisor teeth. stereotypes; this has been reported in more Triggers linked to cribbing than 15% in domestic horses are; events that result in excitement/agitation, whilst they have not been Stable activities (person witnessed in feral horses. traffic, cleaning stables) and manipulations and activities Stereotypes are repetitive of the affected horse behaviours and have no obvious function. (saddling, grooming, eatIn captive horses their ing). feeding is completely different from the natural Wind Sucking often situation; they are regularly occurs with crib biting and fed high energy concentrates is similar though the horse and fairly little forage. doesn’t need to grasp a solid
Stereotypes: The following behaviours are stereotypes, crib-biting, weaving, box walking and wind-sucking. Contributing factors causing this behaviour is the horse’s individual genetic makeup and environmental factors. Stereotypes cause clinical effects such as poor performance, wear of teeth,
object during wind sucking the horse takes in air whilst in cribbing they don’t.
Box walking is when a horse walks around the box, this behaviour makes it difficult to keep bedding fresh and clean. According to McGreevy box walking is reported as 2.20% of 13 population samples. 6
Animal Behaviour
© Horse and Hound Horse Crib biting
Weaving is a locomotion stereotypic behaviour this is demonstrated by the shifting its weight from one foreleg to the other whilst swinging head and neck from side to side. Trigger situations are events that result in agitation, expectation of feed, social activities (people, horses) and activities on the yard (haying etc). A study by McGreevy shows the mean percentage of weaving to be 3.25%.
How do horses learn? Four main ways:
the foal to the stimuli whilst holding the foal so its unable to flee until the foal relaxes. Foals imprint on their mothers in the first few days and afterwards can be desensitised to a wider range of environmental stimuli. This process includes object, feed and sexual imprinting and was found by Robert Miller (1991). The advantages of imprinting are; foal is easier to handle and desired behaviour strategy is established because the foal hasn’t learned an alternative.
Habituation is one of the simplest forms of learning. Imprinting can take place a It’s the fading few hours after the foal has responsiveness for a been born. This can involve picking up the feet, exposure recurring stimulus. It’s a useful learning method to noises, clippers, horse trailers and other frightening because it avoids the horse from responding to harmless stimuli. The idea of imprinting is to habituate the environmental stimuli by a fearful reaction. Its foal by continually exposing
evolutionary advantage is that it conserves energy. Two types of conditioning, classical and operant. Classical is making reflex responses to a new stimulus that has been paired with the original innate stimulus, e.g. moving the lunge whip away when lunging, training the horse to have the same response to the voice, gradually by taking the whip away the responses if purely from the voice. This process is also known as Pavlovian and many behavioural patterns are learnt this way.
Operant is learning by trial and error or learning by success. It’s based on a behavioural pattern being gained by fulfilment or a need for a reward. 7
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Imitation is learning by observation or imitation visually or acoustically where apparent behaviour is copied from a companion. It’s not to be confused with social facilitation. Horses have been around for millions of years and have gone through vast changes this we see the horse of today, which has adapted its original lifestyle in behaviour and appearance. The wild horse although not the same as a domestic both have been subjected to pressures promoting the growth of traits which has meant survival adaptation in a given environment.
Š Authors Photography
Š Brandon Carpenter - Imrpinting a foal
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