In a previous article, this column explored how horses see the world. Their vision differs from humans in many ways including range of vision, clarity, night vision, and depth perception.

As we turn our attention to the cute fuzzy ears on our equine buddy, we wonder if similar differences apply. Horse’s ability to hear loudness (decibels) is about the same as ours. There are, however, differences in range of hearing. The world is part of an acoustical landscape in which sounds are being produced at the very lowest frequencies to the very highest. At the lower end, we humans can actually hear slightly better: down to 20 Hertz versus 55 in a horse, but at the opposite end horses can hear much higher frequencies than us: 33,500 Hertz compared to only 20,000 Hertz for humans.

By comparison, dogs can hear up to 45,000 Hertz, mice up to 91,000 Hertz, and bats even higher. “Ultrasound,” in our species-centric language, means any sound in a frequency too high for the human ear to perceive so one can confidently say that horses have ultra-sonic hearing! Our human ears are tuned to a certain range that makes sense for our survival, and horses’ auditory abilities are tuned to a range that extends much higher. Evolution has determined that it is a survival advantage for horses to hear more animal vocalizations than us.

As with vision, horses are perceiving a more stimulating world than we humans will ever know. Interestingly, horses are not that good at pinpointing exactly from where a sound originates. According to Professor Rickye Heffner of the University of Toledo, this is probably because their vision takes in almost the entire horizon and they can use that ability to figure out exactly where the sound is coming from. Professor Heffner believes that is why a horse will turn his head toward a sound, to compensate for a moderate locator ability in their ears.

All mammals have ears that help them to funnel and amplify sounds. Horses’ ears are well designed for that with ten independent muscles that can move each ear up to 180 degrees and independently of each other. If you are a rider, you will have seen your horse rotate one ear back to listen to you while the other one continues to face forward. This rotation helps them locate the source of the sound, and when used in conjunction with their wide-ranging vision, not much escapes their attention.

Horses also outperform us in their ability to smell, and smell is critical to their survival and procreation. Evolution has given the horse a large and complex olfactory system. Within their nasal cavity are special areas where inhaled air is warmed, mixed and distributed to their approximate 300 million olfactory receptors, compared to our pitiful five to six million receptors. With this advanced sensory ability, horses can avoid poisonous plants, moldy feed, or dirty water. They use their abilities for fun too, seeking out mares in estrous! When I ride Little Bear into the arena, he always wants to sniff all the manure on the ground. He is figuring out which of his friends have been there, or if there is an unknown horse in the area.

Have you seen a horse stretch his neck, raise his upper lip, open his mouth and inhale? This is called the Flehman response. The action engages a special organ in the palate to enhance smells. Horses tend to do this when encountering a strong smell such as a receptive mare, or even a bad tasting worming medicine. This is all part of the horse’s extraordinary sensory abilities. One final note about smell: a study undertaken at the University of Pisa in Italy actually confirms that horses can “smell” fear! When we humans are experiencing strong fear, or even strong happiness, we emit chemo-signals through our sweat. Horses in the study reacted with striking variation in heart rate when they smelled “fear” or “happiness.” No doubt in conjunction with the body language a tense or fearful rider displays, a horse knows what you are feeling even before you do.

It is interesting that not a lot of formal research has been done in the area of horses’ sense of touch, considering that this is the primary way we communicate with our horses: through leg, seat, and bit. But hundreds of years of observation and interaction with horses gives us a pretty good idea of how their bodies process touch. There is no doubt that horses are extremely sensitive. Their muzzle whiskers, known as vibrissae, have a concentration of nerve endings that assist them in understanding what is close to their mouths.

Similar whiskers around the eye stimulate the blink response. Most horse owners do not trim their horses’ whiskers for that reason. Because of a major nerve in the face, the upper nose is very sensitive, which not coincidentally is where the noseband of the bridle rests. It is why hackamores can be more effective than a bitted bridle. A study done in 2017 found that nosebands on eventers and dressage horses are routinely adjusted very tightly to obtain more rider control and to prevent the mouth from opening. Unfortunately, this is at the cost of increased pain in this very sensitive area, and possible tissue damage.

Anecdotal wisdom is that horses do not like to be tickled or patted, preferring gentle stroking. They are touchy about areas with more sensitivity such as the girth, belly, legs, and face. As we interact with our horses, it is best to keep in mind that even though they are huge, they are sensitive. Move quietly around them, be respectful of their bodies, and watch their body language carefully.

In summary, to maximize a strong and productive relationship with our horses, a better understanding of how horses perceive the world is helpful. Their “umwelt” or sensory environment is not ours and we can never experience it firsthand. But by reading about it and observing our horses carefully, we enjoy a better connection with this always fascinating creature.

Tracy Van Buskirk is a 37-year resident of Newtown and president of Newtown Bridle Lands Association, at www.nblact.com, a nonprofit volunteer organization formed in 1978 to foster an interest in horseback riding as well as preserving, protecting and maintaining riding and hiking trails in the community. Horses have always been a part of her life. She owns a small bay quarter horse named Little Bear.