The research team that conducted the study took a deep dive into how horses integrate sounds, voices and emotions. They found that not only do horses develop a corresponding relationship to the sound of the human voice, but the horse brain—like that of humans, dogs, and other animals—also categorizes these sounds based on positive and negative associations.

Right vs. Left Brain

Studies have proven that horses assimilate sounds in distinctly different ways. Negative, stressful, or alarming sounds are processed in the right hemisphere of the brain, while positive sounds, such as the rumble of the feed truck, are processed in the left hemisphere.

Additionally, the horse’s senses, particularly his ears and eyes, are laterally—or oppositely—connected to the brain hemispheres. When a horse looks with his left eye, for example, the right hemisphere of his brain is activated, and when he uses his right eye, the opposite occurs.

A horse that senses an emergency situation will use his left eye and left ear to assess the level of threat. Knowing this information allows researchers to determine how information is perceived emotionally by the horse. A happy, social situation will be “looked upon” from the right-side senses (and the left brain hemisphere is activated), while terrifying situations—such as that ghostly plastic bag in the wind—is predominantly viewed from the left (with right brain hemisphere activation).

How the Study Worked

Based on prior studies of how horses respond to voice, the research crew hypothesized that the horse, even when deprived of other information, such as the familiarity of an owner or facial expressions, would connect a voice to a singular experience.

The study included 21 horses. Over a period of seven days, each horse was exposed to two different scenarios: one in which they were given a tasty bucket of food, and another where they were given the same meal, but this time the food was mixed with vinegar, making it inedible—and frustrating.

The “voice,” a continuous recording of a person reading a script, came from a small loudspeaker worn around the neck of the handler. The voices on the loudspeaker were different for the positive and negative experiences, however.

To provide a balanced assessment, 10 of the horses were from a riding center. These horses lived in stalls and were regularly used for riding lessons. The other 11 horses lived in a pasture environment. They were casually ridden and had daily interactions with people. This second group had continual access to grass or hay, while the riding center horses had more scheduled feed times and less access to roughage.

After the seven-day exposure period, the research team tested each horse. This time an unknown handler led the horse, and the voice on the loudspeaker was broadcast without food. Two video cameras were used to record the horse’s response to the voice for later analysis.

Additionally, 17 of the 21 horses were comfortably outfitted with a portable elecroencephalogram (EEG) helmet on the horse’s head in order to measure the horse’s brain waves. The EEG showed the team which side of the brain was most active during each experiment.

The Conclusion: Horses Respond to Voice

The results were not surprising. Combining the three methods of analysis, the researchers were able to conclude that there is a definite connection between sound and equine response. The team determined from the video that the food treat and coinciding voice was met with a significant increase in ears forward, attentive posture, and approach behavior. In particular, three horses pulled on the lead, with one nickering when the voice was played.

In contrast, the voice associated with the vinegar-laced food was met with an ears-back response and avoidance, with seven of the horses pulling on the lead to move away from the sound. The video also confirmed that for the positive experience, the right eye (associated with positive emotions) was used more frequently, while during the negative experience, the left eye (correlated with fear and anxiety) was significantly more engaged.

Finally, the EEG results, which measured gamma waves, confirmed the hypothesis. The positive experience showed a heightened increase in gamma waves in the right brain hemisphere. Activation of gamma waves are an indication of memory and recall—and, the researchers suspect, the expectation of a future positive event.

Though the difference was small, the researchers also noted that the pasture horses, likely because they were less dependent on the voice-related food supply, showed less frustration at the vinegar food mix.

This study confirms that the bond between humans and horses is by nature emotional, and that the quality of interactions between the two is heard—and remembered. The researchers hope that this study continues to add more information to the growing field of horse welfare.

This article about how horses respond to the human voice appeared in the October 2020 issue of Horse Illustrated magazine. Click here to subscribe!

The post Voice Recognition: How Horses Respond to Voice appeared first on Horse Illustrated Magazine.

The ability to problem-solve is a key part of cognitive intelligence. Personal experiences and anecdotal stories show us that horses are capable of it. Many elements influence innovative behavior. Based on previous research, the scientists focused on age, sex, size, laterality (left or right “handedness,” often studied to establish if left- or right-dominant individuals are more successful at certain tasks), stress level, and task-
related behavior.

Design of the Study

The study, conducted at a riding stable in Bavaria, Germany, took one month to complete. There were eight mares and eight geldings, ranging in age from 7 to 25. Each horse was regularly exercised, fed, and ridden according to their normal schedule.

The horses were given 38 hours to empty, and thereby “solve” the feeder. The feeder was a casing tube with a rod attached at the base (see pg. 18). When nuzzled by the horse, the rod turned a crossbar on the interior of the tube, causing food to tumble into a collection plate. Further nudging shook the food into the horse’s feed trough. Through trial and error, the innovative horse could learn to manipulate the rod in order to receive the food reward.

◆ The motor laterality preference (“handedness”) of each horse was determined by researchers by observing them in pasture prior to the study. In horses, as in humans, the right side of the body coincides with the left hemisphere of the brain, which specializes in activities related to categorization and prior learning. The left side of the body—and right hemisphere of the brain—specializes in emotion, novelty, and social behavior.
Sensory laterality was marked by which eye was used when the horse made both an approach and contact with the feeder.

◆ Stress hormone levels, as measured by glucocorticoid concentrations (GCMs), were taken to establish the general level of stress of each horse.
Three samples were taken prior to the test to create a baseline. Another sample was taken on the second day of the test for comparison.

◆ Task-related behavior was recorded on two motion-activated camcorders during the study. The activity level of each horse was measured as the total amount of time the horse was in motion.

PERSISTENCE was defined as the number of times the horse’s muzzle touched the feeder, while TENACITY was defined by the amount of time the horse spent with the feeder.

LATENCY was measured as the length of time it took for the horse to make first contact with the feeder.

FOOD MOTIVATION was determined before the study began when each horse was given the same amount of food and timed. The amount of time that it took the horse to finish the feed was the measurement of food motivation.

Results Are In

The final results were clear:

◆ Four of the horses had completely emptied their feeder and could be called “innovative problem-solvers.”

◆ Six horses consumed only a portion of the feed and were considered “by-chance problem-solvers,” because it was not clear if they had learned to operate the feeder.

◆ The remaining six “non-problem-solver” horses did not obtain food from the feeder.

The researchers found that age, stress hormone levels from the test day, persistence, food motivation, and height could be eliminated, and sensory and motor laterality could not be fully considered as a factor, because most horses in this study tended to favor their left side.

The researchers did note, however, that all of the four innovative problem-solvers had “significantly higher” left motor preference, and three of the four had similarly higher left sensory scores.

Sex played an interesting role. While the four problem-solving horses were split evenly—two mares and two geldings, all of the by-chance problem-solvers were geldings, and all of the non-problem-solvers were mares.

Final Analysis

In the final analysis, four traits stood out: activity, latency, tenacity, and a high baseline stress hormone level.

In general, successful horses were very active, and they spent the most time engaging with the feeder. Ironically, they were considerably slower to first approach the feeder.
The researchers deemed this combination a sign of inhibitory control—a cognitive process that allows the horse to adjust each try based on past success or failure and hone in on only successful actions.

From this trait combination, the researchers concluded that innovative problem-solvers were “active, tenacious, and have a higher inhibitory control.” Successful horses also tended to be more emotional based on “high baseline stress hormone concentration and a strong left [handedness].” That strong left-side dominance was taken into account as an indicator that problem-solvers saw the problem through the lens of the more emotional right brain.

The researchers suggest these last two traits may be the result of life experiences in which the horses have been exposed to a variety of challenges and activities that required similar problem-solving. They hope that their work will lead to more study and a deeper understanding of the cognitive capabilities of horses.

* Horses’ (Equus caballus) Laterality, Stress Hormones, and Task Related Behavior in Innovative Problem-Solving.

This article about how horses problem solve appeared in the September 2020 issue of Horse Illustrated magazine. Click here to subscribe!

The post The Puzzling Horse Feeder appeared first on Horse Illustrated Magazine.

Despite their reactive reputation, horses are not always easy to read—particularly when they are well-trained. Ol’ Fred may seem calm and cool on the outside, but inside he may be shaking in his horseshoes. A recent study out of the University of Guelph asserts that there is a non-invasive method to assess stress in horses, and it involves the smallest of movements: blinking.

The researchers sought a simple behavioral sign, something that could be understood without complex tests, to determine the anxiety level of an outwardly calm horse. In humans, the number of times a blink occurs fluctuates in response to emotional stress, pressure and focus.

The spontaneous blink, which is not something a horse does purposefully, nor is it something a horse would need to be “trained out of,” neatly fills that gap. Variations on the blink, such as half-blinking and upper eyelid twitching, were also tallied, as they too have been shown to change relative to emotional stimuli.

How It Was Done

The study looked at 33 horses from three different riding stables in Ontario, Canada. All of the horses were lesson horses ranging in age from 5 to 17 years old. In general, well-seasoned lesson horses have been exposed to a wide variety of circumstances and are trained to be cooperative. The researchers wanted to make sure they were able to find a marker of stress, particularly in compliant horses.

There were four components of the study: control, feed restriction, separation, and a startle test. During all of the tests, the horse’s heart rate was recorded, as were any obvious behavioral signs of duress. A video camera recorded eyelid movement.

Except for the food restriction portion, the tests were done during quiet times at the stable when lessons and feeding did not normally occur. Each horse had the same handler and observer for all of the tests, and each test lasted three minutes.

◆ During the control segment, each horse was observed in his regular turnout area with visual access to his stall mates while baseline heart rate and eye-blink rate were taken.
◆ The feed restriction test occurred during normal afternoon lunchtime. Instead of being fed, the test horse was tied in the stall within view of the other horses while they enjoyed their meal.
◆ The separation test took place in a testing arena where the other horses were out of sight but still within earshot.
◆ Researchers performed the startle test in a distant arena where there was no visual access to other horses. There, they threw a ball at a 6-foot distance from each horse and monitored his reaction.

Does the amount of horse blinks indicate stress?

Human studies have found that mentally stressful situations tend to increase blink rate, while visually stimulating tests, such as complicated computer games, decrease blink-rate.

A decreased blink rate is often associated with focused attention and likely allows the participant the advantage of gaining maximum visual information.

Based on this knowledge, the team predicted that spontaneous blink rates would increase during the food restriction and separation tests and decrease during the startle test.

After all the horses were tested, however, a different picture emerged. Each test resulted in a decrease in blinks. While the control segment resulted in about eight to nine blinks per minute, blinks dropped to about five per minute during each of the tests.

The food restriction test proved the most stressful for the horses, and the most revealing for the researchers. When deprived of their lunch, the horses showed an elevated heart rate and definite signs of agitation, such as increased mouthing and restlessness.

Like the other tests, the eye-blink rate was around five per minute. However, the norm of two eye twitches per minute during the control and other tests jumped to six per minute. This was the only test in which eye twitches were noticeably more prevalent.

The separation test and the startle test had similar results: no increase in heart rate and no show of nervousness, but full blinks and half-blinks occurred less often.

These results could be confounding, but the researchers concluded that a decreased blink rate without an increase in eye twitches may indicate a more curious or interested emotional state—one in which the horse is neurologically tuned in.

A Closer Look

The results were clear to the researchers. Of the three tests, food restriction stood out as a glaring stressor. The combination of increased eye twitches and a decreased blink rate held a powerful, though subtle, message—one that an observant handler could potentially learn to read and understand.

This research beckons us to remember that the highly trained horse has learned to contain his natural fight or flight tendencies; however, a thoughtful handler may find insight by simply taking a closer look.

This article about if a horse’s blinking could indicate stress appeared in the August 2020 issue of Horse Illustrated magazine. Click here to subscribe!

The post In the Blink of an Eye: Could the Amount of Blinking Indicate Stress in Horses? appeared first on Horse Illustrated Magazine.

The earliest horses were tiny woodland creatures, the size of a housecat or small dog. They had a springy back and (usually) four toes in the front and three toes in the back. Over millions of years, as the horse grew in power and strength, those toes slowly disappeared. This left one middle digit—the hoof.

Today, only the one-toed horse remains. It’s likely that the question of how the hoof evolved has plagued scientists since the moment the first fossil of a three-toed horse was found. Most agree that the hoof was an adaptation that promoted survival by allowing horses greater speed in order to evade predators. It makes sense: non-aggressive, herbivorous animals make ideal prey.

But a recent study published in Frontiers in Ecology and Evolution begs to differ. After looking long and hard at fossil records and prior research, the authors say that though horses are able to pick up speed when needed, their physiology tells a different story: Horses, they posit, are more suited to trotting—not in retreat—but in pursuit of food.

Mechanics of the Leg

While most prior work has focused directly on the hoof, this study took a wider view by looking at the entire leg of the horse. While the three-toed horse had a similar leg makeup as the hoofed horse, it was really the hoofed horse that has an optimal leg in a mechanical sense.

The interior of the hoofed horse leg is an intricate conglomeration of ligaments, tendons, and bones that work in synchrony to create elastic energy that is stored and released as the horse propels forward. Aptly named the “spring leg,” the effortless strength of the horse’s leg is the real source of its incredible power.

The fetlock joint, as it is winched downward by force when the horse moves, acts like a rubber band or a spring when released. The fetlock is incredibly flexible, capable of stretching down to 90 degrees from vertical. This construction, note the researchers, is the real key to the survival of the horse.

Not only does it allow for tremendous power, but it’s also extremely efficient because the snapping back action, like that of a bow and arrow, is a passive movement that requires less metabolic stores of energy.

The authors assert that though energy is saved this way at all gaits, it is at the trot that the horse is most efficient—leading them to solidify their hypothesis that horses are well-equipped to spend most of their time trotting across long distances in search of grazing lands.

Working with the Back

In addition, the anatomy of the horse’s back confirms this conclusion. By this time period, the horse had evolved to have a shorter, firmer, and less flexible back. Flexibility in the back would also provide elastic energy and is necessary when horses run at high speeds, as the back end of the horse curves under to take long strides.

But a less-flexible back, when combined with more spring-like legs, would not hinder the more vertical movement seen when a horse is trotting. The authors evidence this by the fact that horses in the wild trot naturally across grassland, endurance riders often utilize the trot, and even the U.S. Cavalry preferred the trot as a form of efficient travel.

It is convincing that an energy efficient leg and a sturdier back would enable the horse the required endurance that would be necessary to search for food. But what was confounding for the researchers is that the three-toed horse also had a spring leg, and even though it was less developed, the question remained, why did the hoofed horse eventually become the sole survivor while the three-toed horse became extinct?

Changing Climate

The researchers next looked at climate. The one-toed horse first appeared in North America approximately 15 million years ago during the late Miocene era. This was a time of warm, moist temperate weather in which three-toed horses and hoofed horses both thrived and lived alongside each other.

The landscape was primarily woodlands, which provided ample food sources for a variety of horse species. Three-toed horses were thought to have an advantage in muddy footing, with their extra toes providing them better balance and maneuverability. At this point, hoofed horses were just a small part of a larger, richly diverse group of horses—most of which remained three-toed.

Over the next 10 million years, the three-toed horse began to decrease in size and diversity as significant weather changes occurred. The climate became drier, colder, and less hospitable. As arid grasslands replaced fertile woodland, three-toed horses found their preferred habitat continually shrinking to the southern regions.

One-toed horses, with that stronger, more efficient leg, had a much wider territory to choose from, and their foraging behavior, which prioritized the more prevalent grasses, followed suit. By 1 million years ago, only hoofed horses remained as all other horse species gradually disappeared.

The authors of this study rest on the conclusion that the hoofed horse evolved not because the single hoof had any particular advantage over the three-toed horse, but because climate change created an environment that allowed this horse, with its already built-in efficiency of locomotion, to take advantage of a larger range of foraging.

Their perspective is that the hoof, along with the superior leg, encouraged the hoofed horse to travel long distances. This ability to roam and rely on grass as a food source inevitably helped them survive while others went extinct.

In the author’s own words, “Equus was fundamentally a lucky genus in the grand scheme of equid evolution.”

Source: www.frontiersin.org/articles/10.3389/fevo.2019.00119/full

This article originally appeared in the July 2019 issue of Horse Illustrated magazine. Click here to subscribe!

The post Evolution of the Hoof appeared first on Horse Illustrated Magazine.

The study, which took place in Brittany, France, was meticulous in its approach. Researchers began by looking at 48 horses in three basic settings: lesson horses living primarily in a stall, lesson horses with access to pasture and barn equally, and pasture horses ridden casually.

Happiness vs. Stress

Before jumping in and recording snorts, the researchers categorized horse behavior that likely indicated happiness, such as an interested demeanor and relaxed ear position. They also established clear markers of unhappy behavior, such as ears pinned back in aggression or a show of disinterest, such as when a horse is facing a corner or wall.

When observation began, snorts were reported using a microphone and recording device. At the same time, the observer documented the activity the horse was engaged in and any relevant information necessary to assessing the horse’s mood.

To get a sense of each horse, the researchers created a “total chronic stress score” (TCSS). In particular, they noted conformation issues, such as a swayed back, which may cause pain and affect the horse’s general outlook. Symptoms of emotional distress were also logged, such as cribbing, weaving and head shaking, or aggressive behaviors like ear-pinning, biting and kicking.

Counting Snorts

The researchers hypothesized two things:

1. Horses in more natural circumstances snort more. This would indicate that snorting is indeed a reflection of contentment.
2. Horses with lower total chronic stress snort more in general. This would also indicate a link between snorting and overall happiness.

Once the snorts were counted (560 in all) and organized into categories based on the circumstances in which they were heard, the results were crystal clear. Snorting is more prevalent when a horse is in a pleasant situation, and horses living in less stressful conditions snorted more often. All of the horses tended to snort most while eating, during calm observation, or while quietly meandering around the pasture.

Looking at the two riding school groups of horses, 189 snorts were heard while the horses were in their stalls, while 265 were heard when the horses were in the pasture. More significantly, no snorts were heard when a horse was aggressive or facing the stall wall.

Eight of the horses never snorted in the stall at all during the times they were monitored. Habitual or negative behaviors, often seen while horses were in the barn, were absent when the horses were at pasture.

Pasture Contentment

Overall, the horses living continually in the pasture elicited the most snorts. The riding school that allowed their horses 50 percent time at pasture had almost as many snorts recorded as the pasture-only horses. The last group, in which the horses spent the most time in stalls, had the least number of total observed snorts.

Perhaps the most interesting moment for the researchers came when four of the naturalistic horses were moved to a larger pasture with an abundance of grazing. During this time, the horses produced up to 10 times the number of snorts per hour than they had in their original pasture.

While the specific purpose of this study was to determine the meaning behind the snort, it was not difficult to read between the lines. Overwhelmingly, it seems evident that horses, as herd animals, appreciate circumstances that allow them to be with other, familiar horses.

Additionally, riding in a casual, loose-rein style allows the horse more mobility, which is associated with less back pain. The solitary barn stall, considered the Shanghai-La of horse homes, may not be making your horse happier. Instead, access to pasture—the more the better—allows horses to graze and socialize in a setting to which they are best suited.

This study sends a definitive message. Horses are by nature humble creatures that have few basic needs: horse buddies, a field in which to roam, and exercise in a relaxed manner. When your horse is happy, you’ll hear it in a simple snort.

* “An Unexpected Acoustic Indicator of Positive Emotions in Horses”: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0197898

This article originally appeared in the January 2019 issue of Horse Illustrated magazine. Click here to subscribe!

The post What Does it Mean When a Horse Snorts? appeared first on Horse Illustrated Magazine.