Carey A. Williams, Ph.D., Extension Specialist in Equine Management, Rutgers University
A horse’s vision is its primary detector of danger. Even though they have poor color vision, they can differentiate blue and red from gray hues. However, they have more trouble differentiating yellow and green from gray. Horses also have poor depth perception when only using one eye. They can’t tell a trailer from an endless tunnel, or a mud puddle from a bottomless lagoon. Their perception is improved by about 5 times when using both eyes (binocular vision). They can instantly change their focus from near to far objects. This is why horses cock their head in different ways to see close vs. distant objects. Horses have an acute ability to detect movement. This is why a horse is much flightier on windy days; things that are normally stationary are now moving and perceived as a potential threat. Horses are able to see fairly well at night; however, the contrast sensitivity is less than that of a cat.
The mechanics of a horse’s vision is different from our own. They can see almost panoramically, with a small spot directly in front and directly behind as their blind area (see Figure 1). Never approach a horse without talking to them in these areas; if frightened they will use one of their defense mechanisms, e.g., kick or run. A horse can see two things at once, one from each eye. That allows each side of its brain to work separately. Like humans, horses have a dominant side (right-handed or left-handed); however, unlike humans, horses need to be taught things twice: on the right side and on the left side. The expression in a horse’s eye is often thought to be a good indicator of their behavior, e.g., wide open with white showing (and not an Appaloosa), scared; half closed, sleepy, etc.
A horse’s hearing is much keener than ours. They use their hearing for three primary functions: to detect sounds, to determine the location of the sound, and to provide sensory information that allows the horse to recognize the identity of these sources. Horses can hear low to very high frequency sound, in the range of 14 Hz to 25 kHz (human range = 20 Hz to 20 kHz). Horses’ ears can move 180 degrees using 10 different muscles (vs. 3 for the human ear) and are able to single out a specific area to listen to. This allows the horse to orient itself toward the sounds to be able to determine what is making the noise.
Horses’ tactile sensation or touch is extremely sensitive. Their entire body is as sensitive as our fingertips. They can feel a fly on one single hair and any movement of the rider.
Horses are good at letting us know exactly how they are feeling; the only problem is most people don’t know how to speak “horse.” So here are some tips on reading a horse’s body language.
If a horse’s tail is:
If a horse’s legs are:
Some horses’ facial expressions include:
The horses’ ears are a unique feature:
Horses have a variety of methods of vocal and non-vocal communication. Vocal noises include a squeal or scream which usually denotes a threat by a stallion or mare. Nickers are low-pitched and quiet. A stallion will nicker when courting a mare; a mare and foal nicker to each other; and domestic horses nicker for food. Neighs or whinnies are the most familiar: high pitched, drawn out sounds that can carry over distances. Horses whinny to let others know where they are and to try to locate a herd mate. They also respond to each other’s whinnies even when out of sight.
Blowing is a strong, rapid expulsion of air resulting in a high pitched whooshing” sound, which usually is a sign of alarm used to warn others. Snorting is a more passive, shorter lower pitched version of blowing and is usually just a result of objects entering the nasal passage.
In contrast to signals of aggression within a herd, there are also signs of friendship. Mares and foals nudge and nuzzle each other during nursing or for comfort, and mutual grooming, when two horses nibble at each other, is often seen.
A herd of wild horses consists of one or two stallions, a group of mares, and their foals. The leader of the herd is usually an older mare (the “alpha mare”), even though one stallion owns the herd. She maintains her dominant role even though she may be physically weaker than the others. The older mare has had more experiences, more close encounters, and survived more threats than any other horse in the herd. The requirement of the lead horse is not strength or size; if this were so, then humans could never dominate a horse. Dominance is established not only through aggression but also through attitudes that let the other horses know she expects to be obeyed.
The stallion’s job is to be the herd’s guardian and protector, while maintaining reproductive viability. The stallion’s harem usually consists of 2 to 21 horses, with up to 8 of those being mares and the rest their offspring. When the colts are old enough to be on their own they will form a bachelor herd. The fillies will either remain in their natural herd or more commonly disperse into other herds or form a new herd with a bachelor stallion. As soon as a stallion becomes too old to maintain his status as herd owner he is replaced by a younger stallion from a bachelor herd. The average time for a stallion to remain leader is about 2 years, but some can last more than 10 years.
Horses are most vulnerable when they are eating or drinking. So, when a horse is being submissive, it will simulate eating by lowering its head, chewing, and licking its lips (similar to snapping mentioned above). Dominance occurs when a horse forces the other to move against its will. One horse will move its body in the direction of or in contact with the other forcing it to move. Fighting usually occurs when the dominant horse is challenged by the other horse not moving, or responding aggressively.
Vices are negative activities that occur due to various causes, including stress, boredom, fear, excess energy, and nervousness. Horses naturally graze for 12 to 16 hours a day. When kept in stalls we prevent them from engaging in many natural activities such as grazing, walking, or playing with other horses. Not enough natural stimuli will cause a horse to invent its own stimuli. Once these habits start they are difficult to eliminate.
Cribbing occurs when the horse bites onto a fixed surface (e.g., stall door edge, grain bin, fence rail), arches his neck and sucks in air, making a grunting noise. This causes a release of endorphins which relieves the unpleasant situation. Cribbing becomes addictive; even when removed from the unpleasant situation the horse may still crib. Some horses even prefer cribbing to eating! Cribbing can lead to weight loss, poor performance, gastric colic, and excessive tooth wear.
Weaving occurs when the horse stands by the stall door and rhythmically shifts its weight back and forth on its front legs while swinging its head. This is also caused by boredom or excess energy, and can lead to weight loss, poor performance and weakened tendons.
Stall kicking, stall walking, pawing, or digging, and biting over the stall door are also vices that are caused by boredom from being kept in a stall. To decrease the frequency of this behavior, you might try adding another mealtime, placing toys in the stall, or providing more roughage or turn out time.
Wood chewing, eating bedding, or dirt, and self-mutilation are caused by lack of exercise or boredom. However, nutritional deficiencies could also cause these vices. To eliminate this as a cause, provide more roughage in the diet, and free choice salt or minerals. This may decrease the frequency of the vice.
For more information on horse behavior, check out the Horse Survival Learning Lesson.
Keiper, R.R. 1986. Social Structure. Veterinary Clinics of North America-Equine Practice. 2: 465-484.
McDonnell, S. Equine Behavior Lab, University of Pennsylvania, School of Veterinary Medicine. www2.vet.upenn.edu/labs/equinebehavior/
Miller, R.M. 1995 to 1997. Behavior of the Horse. Journal Equine Veterinary Science. Volume 15(1) to Volume 17(4).
Timney, B., and T. Macuda. 2001. Vision and Hearing in Horses. Journal of American Veterinary Medical Association. 218:1567-1574.