Understanding a Horse's Senses
To see things from the horse's perspective, you need to know — literally — how the horse takes in the world. Humans evolved to be hunters and gatherers, chasing down prey and finding appropriate plants to eat. Horses, on the other hand, are built to avoid hunters and eat nearly everything that grows around them. Given these fundamental distinctions, the horse's senses are bound to have nuances that are somewhat different from those of a human.
Sight is the most important equine sense. For a prey animal like the horse, in the wild, good eyesight means the difference between life and death. Literally seeing trouble coming is the best way the horse has to make it to safety before a predator gets too close.
Because horses have long, narrow heads with eyes on either side, they have the ability to take in more of the view than humans do. When their heads are facing forward, horses have a nearly 180-degree field of vision. They can see in front of and almost all the way around their bodies, though they do have some blind spots.
One of a horse's blind spots is directly behind, so you should never approach a horse from the back unless the horse already knows you're there.
No one knows for sure how far horses can see, mainly because horses have trouble pronouncing the letters on eye tests. Scientists who have done experiments in this field have made some educated guesses that horses can see pretty darn far, in the realm of at least hundreds of yards away. Horses can distinguish patterns, which means they're able to take in fine details. They can also perceive depth well.
Horses also have much better night vision than humans. Many a rider has been out on a dark, moonless trail, dumbfounded by his or her horses' ability to see where the pair are going despite the incredibly dim light.
Scientists know far less about horses' color vision than about other areas of equine sight, but they are certain that horses can see some colors. Red and blue seem to be particularly distinct to the equine eye, but beyond this, we don't know. Researchers need to do more tests to find out whether horses can see the full spectrum of the rainbow.
A species that survives by getting a head start on marauding predators needs a pretty good sense of hearing. The fact that horses have survived all the way to modern times is testimony to their incredible hearing, which is considerably better than a human's.
If you look at the shape of the horse's ear, you can see that it's built sort of like a funnel. With this design, the ear can capture sound in its outer part and channel it down into the ear canal. The broad outer part of the horse's ear very adequately takes in the slightest sound in the horse's environment.
Using very mobile ears, horses constantly monitor the world around them. Just imagine trying to pay complete attention to different sounds coming in to either ear at the same time. Impossible for a human, yet the horse does this on a steady basis. A horse can take in the sounds of a car driving by, children playing, a bird chirping and a human approaching, all at once, from different places in the environment. The horse then processes that information and makes split second decisions about whether to react — all while picking out the best blades of pasture grass or meandering down a rocky trail. The process really is mind-blowing.
Loud, unfamiliar noises can send a relaxed horse into a tizzy. On the other hand, a placid, reassuring sound can ease a horse's worries. It's amazing to see how a frightened horse can be comforted by a soft, gentle voice from a calm and confident human. Keep this fact in mind when handling your horse in a particularly noisy or frightening environment.
Like most non-human animals, horses have an acute sense of smell that they regularly employ to provide them with information on what is going on around them. Horses use their sense of smell in a number of different and important ways.
Nature equipped the equine with a strong olfactory sense that can tell the animal whether a predator is near. All it takes is a strong upwind breeze to bring a dangerous scent to the attention of a wild herd. After getting a whiff of the predator, the herd literally high-tails it (their tails stick way up in the air as they flee) out of there in a flash.
Horses also use smell as part of their complicated social structure. Horses typically greet each other nose to nose, each taking in the odor of the other. Horses also come to recognize each other by scent as well as by sight. Mares and foals quickly memorize each other's scents and use this information to help locate each other in a crowd of horses.
Most horses also greet humans in the same way. When you introduce yourself to a horse for the first time, notice how the horse reaches out his muzzle to sniff you. Given this, the most polite way to approach a horse is with the back of your hand extended so the horse may take in your personal scent. Letting a horse breathe in your scent tells the animal that you are a fellow herdmate (not a predator), and usually makes the horse more agreeable to being handled.
The equine sense of touch is an important (although often overlooked) element to the horse. Although many people think that horses have a tough hide, they really don't. Their skin is tougher than our human epidermis, but it is still rich with nerve endings.
If you sit on a pasture fence and watch a herd of horses for a few hours, you'll see plenty of evidence of how horses use touch to communicate with each other. Mothers reassure their babies with a brush of the muzzle; comrades scratch each other's itches with their teeth. Whenever a message needs to be sent from one horse to another, visual cues and touch — or the threat of it — are nearly always used.
Humans can also use touch to convey messages to the horse. A gentle rub down, a pat on the shoulder, a vigorous massage in just the right place — these are all ways of saying, "I'm your friend" to a horse. Sometimes, if you're lucky, you'll get a similar tactile message in return.