last revised: April 12, 2017.
Typical leadership in horses: none.1
Trainers think horses crave leadership
A common premise in natural horsemanship is that “horses need leadership.” This notion draws from the imagination, where we wonder what we would do if left on the plains with strangers. With humans, we imagine, someone would choose to become the leader, and would cheerfully make decisions for us. Governments would form, and we would submit.
Trainers seem to believe that horses are looking for leadership, that the way to have a good relation with a horse is to be that leader. “Leader” in this context is undefined, but could mean “boss” or “bully”.
Linda Parelli seems to think that leadership is impossible to avoid — that either your horse leads you, or you lead him. She writes “Horses need leadership both on the ground and in the saddle. Leadership is essential to them in the wild; if they don’t have a leader they will become one and make all the decisions as to when to go, when to stay, and when to run. So if you don’t lead, they will.2”
Tim Hayes believes that if a horse refuses to do what you ask, “no matter what situation is occurring the problem is always some form of horse resistance and the solution is always some form of human leadership… In the natural world, horses have leaders and live in herds. Their leader must have and demonstrate superior survival skills. They must be the most intelligent, confident, perceptive, and sensitive. They must have acquired the most survival experience and, therefore, the most wisdom. In a herd of horses, this is known as the Alpha. There is always an Alpha or leader whether it is a herd of 100 horses or a herd of two—you and your horse.3”
Julie Goodnight has much to say about leadership. She writes that horses “crave leadership and authority and they feel safe and content in its presence. Leadership is very black and white to a horse and he knows it when he sees it. There is no faking leadership to a horse… Horses recognize true leadership—fairness, courage, authority, confidence, intelligence, honesty, responsibility… When your horse thinks of you as the supreme leader, he will go anywhere with you, trusting you to look out for his well-being, having faith in your decisions and knowing you have his best interest in mind… Once your horse recognizes the qualities of a true leader in you, it means that he trusts you to be fair, consistent and protect him from anything that could hurt him… To be accepted as the leader, you have to establish authority right away and not worry about being liked — that will come later. You have to take charge, establish the rules and demonstrate your willingness to enforce them. Then your horse will come to accept your authority, feel safe in your presence and be eager to please you.4”
Apparently none of these authorities have ever watched a herd very closely, as you’ll see below.
Dominance over your horse
Those who are eager to tell you that “horses are herd animals and need leadership” seem also eager to tell us that “horses are prey animals.” Humans, they acknowledge, are predators.
I don’t understand the logic. Doesn’t a horse want to move away from a predator? Under what circumstances does a horse choose to follow a predator, or be ridden by one? Perhaps horses are not quite as fearful of predators as we imagine. Or perhaps we aren’t quite as scary as we’d like to think.
For us to be leaders, these folks tell us, we must establish dominance over the horse. Any talk of dominance attracts an eager following, because many regard their horse (or the horse in the next stall) as “pushy”. If a horse dominates, the fearful rider is in trouble.
The Search for Leadership in Horses
It is a popular idea that age, sex and dominance equate to leadership, which is critical to moving the herd from one location to another.
You are standing in the round pen with your horse, who is at liberty. You set off to the other side of the pen. Your steed does not immediately heel at your side. You call him, but he does not come. A trainer is likely to tell you that you are not showing leadership, and that your horse does not respect you. The trainer has a solution, fortunately: more training for the horse, more money for the trainer. The “training” often involving hundreds of laps in the round pen and/or some form of discipline.
In the Boy Scouts, it is easy to figure out who the leader is. He is the big guy. With horses, determining leadership is a little trickier.
There are three common operational definitions — definitions that come from measurable behavior — of leadership in horses.
- Sometimes the leader is considered to be the horse who chooses to walk away from the herd.
- “Recruitment” — a horse getting another horse to follow them — is sometimes seen as a sign of leadership.
- And when two are walking together, the one in front is often called the leader, and the others “followers”.
While it is common to talk about leadership when talking about the human-horse relationship, you’ll find little research done by scientists on leadership among horses. And this is probably because it doesn’t occur. Marie Bourjade and her colleagues recently spent hundreds of hours over a two-year period observing Przewalski horses in a semi-free range setting. She concludes “Leadership is commonly invoked when accounting for the coordination of group movements in animals, yet it remains loosely defined. In parallel, there is increased evidence of the sharing of group decisions by animals on the move. How leadership integrates within this recent framework on collective decision-making is unclear. Here, we question the occurrence of leadership in horses, a species in which this concept is of prevalent use. The relevance of the three main definitions of leadership – departing first, walking in front travel position, and eliciting the joining of mates – was tested on the collective movements of two semi-free ranging groups of Przewalski horses (Equus ferus przewalskii). We did not find any leader capable of driving most group movements or recruiting mates more quickly than others. Several group members often displayed pre-departure behaviours at the same time, and the simultaneous departure of several individuals was common. We conclude that the decision-making process was shared by several group members … and that the leadership concept did not help to depict individual departure and leading behaviour across movements in both study groups.5”
I am skeptical that herds of horses have leaders. “Leadership” is a term from the Boy Scouts or military, and has no natural counterpart in animals who make collective decisions. I never refer to “leadership” when talking about horses — except to poke at those who use the word. I am a skeptic for many reasons.
- Remember that horses are not the same as all other animals in every way. Gorillas, wolves, feral dogs, elephants, and mongooses seem to have an older individual that they recognize as leader.6 But flocks of birds don’t have a leader. Schools of fish don’t have a leader. Herds of cows don’t seem to have a leader. Swarms of insects don’t have a leader. Many animal groups seem to be leaderless. Birds, fish, cows, and insects all seem to do fine without a leader. This is because leaderless groups can behave as if they had a leader — more on this below.
- Watch your herd to see who is fighting for status. You will never witness such a fight. Watch to see who is wrassling in any way. I think you’ll find that most of the chomping that horses do on each other is done by friends, of equal status in the herd, during play. A dominant horse at food, water, or gate might threaten another, but you’ll never see fighting in your herd. Dominance does not seem to be achieved by violence, unless we add a mare to the mix.
- When I stand and watch horses in a pasture, I see no leadership at all. Everyone is dispersed grazing. They aren’t looking for leadership. The eyes and ears and nose of all are monitoring for possible danger, and anyone is permitted to sound the alarm, anyone is free to begin moving away from danger they have spotted. If those same senses spot someone at the gate with a feed bucket, there is no leader that must be waited for. A herd of domestic horses does not seem to have a leader any more than a flock of geese or chickens. So watch your own pasture for a few hours with a notebook. Is the first horse to walk away from the group always the first to do so? Do others follow him more than they follow the others? When they all come to the gate, does this same horse now lead the group?
- We have science that reaches the same conclusion. One study concludes “We found no horse which could be qualified as the leader in the two groups of Przewalski horses, whatever the definition used to recognize leadership. No individual consistently moved first, elicited faster joining by group members than other first movers, or consistently traveled in front position.7”
- Horses show no sign of feeling secure when confined with a bossy horse. If anything, when a low ranking horse is in a small pen with a dominant horse, the low ranking horse feels nervous, and keeps his distance. They show plenty of security, though, when they are with those of their own rank. A dominant horse that chose to lead would likely have no followers.
- With horses, “leadership” is not a stable personality trait, but rather a behavior that occurs in some situation. My horse will follow me across most gullies or streams or bridges when I am on foot, but when I am on his back, my influence is diminished. I honestly have no idea how scaring your horse into doing laps in the round pen will improve his respect for you or your leadership when you come to the next bridge. In her book on the power of the herd, Linda Kohanov writes of her herd of two mares and one stallion “… The dominance hierarchy varied, quite frankly, according to what the human observer defined as important. In reality, however, the horses were trading leadership and dominance roles according to who was calmest, clearest, most committed, or most invested in the outcome. I noticed similar situational leadership dynamics in the other herds…8”
You might argue. You’ve seen “leadership”. Perhaps you’ve watched the jostling: If there is a big round bale in the pasture, and the grass is sparse, then the horses may be clustered around the bale. One may be standing just where he wants, while others may be taking one of the remaining available spots. What else is there to do in the pasture? Get a drink? Again, there might be a bully, and horse number two might need to wait his turn. But I would not call the one who had first choice a leader. He hasn’t led anything. He has bullied his way in, and threatened any other horse that was standing too close for his liking. But bullying isn’t leading.
Mark Rashid has reached the same conclusion. “I’d been under the impression that most horses within a herd looked up to the boss horses with a sort of awe or with underlying respect. But as I watched the herd react to Otis and Captain, I got a whole different picture of how the horses looked at their leaders. It wasn’t with awe and respect at all, but rather with mistrust and, in some cases, downright fear. In fact, the majority of the herd usually did everything they could to avoid any contact with the boss horse.9” Nobody likes to be bullied.
Collective Decision-Making and Life without a Leader
A herd of wild horses has no leader. Nor does a herd a flock of geese. In the herd, everyone grazes peacefully, and walks to the water hole together. Everyone works together to defend against the dangers of the night. Of course, decisions must be made on which way we should go now. Some horses will be more influential in such decisions, and with our notebooks we might record that they are the leaders. But the entire herd is free to not follow the leader. Everyone votes with their feet, and if “the leader” starts to walk off, and no one follows, she comes back and must wait until they are willing to follow.
I can tell that you are resisting where this monologue is going. Hang tight. This one is hard.
How does a herd make decisions without a leader? In fish, birds, insects, and horses, the answer is that there is collective decision making. In the group, all desire to be close to each other. But this affiliative desire is not the only desire. Sometimes a horse will want to be with the herd while also wanting to be elsewhere. He’ll stand with the herd until his desire to be elsewhere exceeds his desire to remain with the herd. He’ll begin to move off. Now it turns out that he wasn’t the only one who was thinking about being elsewhere. Someone nearby will join him if their desire to be elsewhere was also strong. Their desire to be elsewhere might not have been quite as strong as the desire of the first to leave, but they know that they’ll at least have the company of the departing member, so leaving will be easier. This same thought process passes quickly through the others, and individuals begin to depart quickly, simply because they now have two groups they can be with, but they’d prefer to be leaving. The last to leave may have had no desire to be elsewhere, but a strong desire to be with the group, and the group is going, so they must go too.
When a flock of starlings rises from the field as if in unison, we marvel. Humans expect that to choose a new leader, we will need to spend months campaigning, voting, inaugurating. But schools, flocks, and herds need no conductor or voting process to reach a decision.
This might be easier to understand with a flock of geese. One goose decides it is time to fly down to the river. She gives a honk which is understood to be “Let’s go!”. She has turned to face the wind and may give a head toss. If someone else has been thinking this, another “Let’s go!” might be heard, and this goose too may orient with the first, into the wind. With two such calls back-to-back, others might agree, or come to agree, and say the same. Now the whole flock is facing in the same direction, saying “Let’s go!”, tossing their heads a bit. A few stand up tall and give a few wing flaps. Finally, when there is some consensus — a local quorum — the flock walks forward, and all seem to jump into the air at once. Watch a video so you can study the sounds and their timing. You’ll see that those who are about to fly are already arranged, more or less, in a V, and the entire group jumps into the air at once.10
But things don’t always go this way. One goose decides it is time to fly down to the river. She gives a honk which is understood to be “Let’s go!” She does her head toss. She stands and flaps her wings. No one answers. No one goes. The first goose has to choose between flying alone or waiting. She almost always chooses to wait. Leadership requires followers, and the same oxytocin glue that holds fish and birds together in groups also binds your horse to his herd. When horses are content grazing, they’ll follow no one, and have no leader.
But isn’t the goose at the front of the V the leader? Well, we have to say that she is leading. But if you watch long enough, you’ll see that sometimes someone in the middle of the flock veers off, and her arm of the V breaks away with her. Perhaps the flock splits, or perhaps the others elect to join the group that has split off. And we know with certainty that it is a lady that is leading. We know this by noting that the males are larger than the females, and that with each pair that takes off, he chooses to follow her. We know the V does not form out of a brilliant analysis of aerodynamics, but rather by the need for each goose to see where it is going, and to be able to avoid a collision if someone ahead swerves. (Geese are not like flies, who can turn on a dime. They are more like flying cinder blocks, and need to be prepared for trouble.) We know that the strongest fliers don’t lead, because they’d then need to worry about whether the group is keeping up. The males, who follow their wives, are the strongest fliers, and prove it by demonstrating whiffling — spilling air from their wings — as they come in for a landing. The principles of goose flight strike me as a good template for understanding the principles of herd movement. Mother nature is efficient. She only invents a few principles, and uses them everywhere.
Why would the boys follow the ladies? Neurochemistry might underlie our views of independence. Cortisol is known to trigger separation anxiety, and as we get closer to our group, cortisol goes down. One study11 has found men to have higher cortisol levels than women, suggesting that they — and perhaps male geese — feel more anxiety about being separated. Leading a group is choosing to separate. Following the leader is choosing to stick together.
Leadership in a herd of horses often comes from an older mare. It always comes from a confident horse. A horse who is more comfortable walking away from the others, confident in the value of the water or grass or safety in this direction, will not be pulled back into the herd quite as fast when no one immediately follows. And so the magnetic qualities of a herd — the desire for proximity with others — draws the herd a bit in the direction she has taken. But leadership comes not from dominance, not from aggression, not from wisdom, but from confidence. One study of a band of horses12 calculated an index of nervousness for each horse, and found that those getting to a drinking area first had low nervousness scores, and those initiating flight had high nervousness scores. In this study, no single horse acted consistently as a leader.
Nervousness or anxiety is something we should ponder. When two horses approach water, is it the dominant one who gets there first, or the most nervous one who gets there last? Surely putting your head down to drink entails some risk, and both might be feeling anxiety. When cattle are forced to enter a chute for a dip, is it the dominant one who is in front? I doubt it. No self-respecting cow wants to take a chance on such a sketchy project. But those that have done it before may be less nervous than those who get to the back of the line. While we like to think that the one at the front of the line is the most aggressive, we might be better off sometimes thinking that the one at the back is the most anxious. She may have expended her aggressiveness in a struggle to get to the back of the line. Herd animals spend much of their day worrying about things, and have little time for aggression. Maybe we should think about things differently.
A horse’s confidence varies from one situation to the next. Your confident trail horse heading out over familiar trails becomes less confident when he reaches the dreaded bridge, and his confidence is briefly destroyed by terror when that heron or deer leaps up from the side of the trail. Confidence is a state, not a trait. Confidence can be acquired by habituation: bomb proofing provides repeated exposure to something that was once scary. Providing there is no unpleasant experience wrapped in with the exposure, familiarity breeds comfort and confidence.13
In general, it seems to me that it is riders that are not confident. Many fear being stepped on or bitten or rubbed by a horse. Fear losing control. Fear falling. A horse that fights the bit or that bucks is eligible for a disciplinary clinic or a trainer, followed by sale if he continues to inspire fear. Any program that explains how a rider can show leadership will appeal to one who feels ignored or disrespected by his horse. Many horses might appreciate some coaching in how to sell their fearful owners.
Horses don’t need leadership. It is rare that they even need more confidence. But riders need confidence. They could achieve this without any reference to leadership. And they’d likely be better for it.
Our own reaction times are far slower than those of fish or birds or horses, and decision-making can take days or years. Those of a flock of starlings or herd of horses can often be measured in fractions of a second. Once a very large flock of birds snapped a high tension power line by taking off “at the same time”. When it takes off, a bird jumps into the air, and each jump pushes down. If their takeoffs where like those of humans, nothing would have happened to the line. But birds can react quickly to each other, making their jumps seem (to both human observers and power lines) simultaneous. As a result, a power line is suddenly very heavy.
Remember that next time you find yourself on the ground next to your horse: your horse decided to make a move long, long, long before you could react. Once upon a time, when my horse and I were both surprised by a herd of deer jumping up out of the tall grass right next to us, he was back at the barn before I hit the ground. He’s a quick thinker. I guess I’m not.
I’m not the only one to believe that the word “leadership” has no place in our horse vocabulary.14 I hope you will work at removing “leadership” from your vocabulary when you set out to explain your horse to someone. If we can set aside the silly word “leadership”, we can move forward into some additional quicksand…
Girls rule in most species of mammals, but there are several different models for how this happens.
- In mammals that don’t form herds, such as bears and raccoons, a mother has only a brief interest in the males, and once they’ve done what they’re good at, she drives them off. The males float away, to less desirable territories, and make do until next breeding season. The moms build their dens, give birth, nurse and raise the little ones, and let them follow for a year (raccoons) or two (bears), learning by imitation through careful study of mom.
- In some herd-forming mammals, such as elephants and deer, a mother has little interest in adult males for much of her year, but will indulge a suitor when her hormones are right. She takes care of her young in the same way that bears and raccoons do, protecting them, sometimes grooming them, and providing them with a good role model. Daughters stay with mom, and eventually raise their own little ones in the herd, so the young ones have an opportunity to be cared for by both aunts and grandmothers, and a chance to play with sisters and cousins. Little boys wander off — or are driven off — at puberty, helping to avoid inbreeding. As they reach their prime, they may seek out receptive females in herds they encounter. The herd, bound together with female glue, is able to remain in tact even as males come and go.15
- In elephants, it is a wise old matriarch or two that can lead the herd to a distant watering hole in a drought, to greener pastures long neglected, or to a refuge in a storm. The old gray cow ain’t what she used to be, she’s better, with a longer memory than anyone else, and more information on scarce resources. Following the matriarch during a resource shortage requires just two things: she has a good memory, and knows where she wants to go, and others trust her wisdom and are content to follow. This principle works with elephants when times are tough. The role of oxytocin and cortisol and self-confidence in following the matriarch needs to be studied.
- In other herd-forming mammals, such as zebras and wild horses, mom takes good care of all her children, but then helps dad drive them off as they reach puberty. In such herds, the fillies that have been driven off from one herd will join another. The colts might join a mixed band, or if none seem willing to take him, might find a bachelor band to join.
Most of the boys sit at the edge of the dance floor. A stallion may be able to join a herd and remain with it throughout the year — until successfully challenged by another roaming stallion. There are times of the years when bucks and does may travel in mixed company. But whatever the details, the herd is matriarchal, and builds on the interconnections of mothers and daughters, sisters and cousins and aunts and grandmas. Though men believe otherwise, the world does not have much use for us.
The efforts of a feral stallion to drive his mares from one place to another is called herding, and is not much different than what cowboys regularly do. The stallion moves systematically behind the females, but unlike cowboys, holds his head low and pins his ears back in a threat posture. Sometimes he moves his head from side-to-side, a behavior called snaking.16 This is a standard aggressive display in mammals, and baby raccoons will use it to drive off big adult males of other families. The raccoons resemble a snowplow, but stallions look more like they are trying to get under a low bridge. To a mare, the posture may look like it is a prequel to aggression, but herding includes no actual biting or fisticuffs.
A feral horse stallion (leftmost horse) is herding females in his band by posturing and actively driving his females back into a cohesive group. Herding is the most common social behavior expressed by the dominant male toward females in his harem. It is useful to him, because a tightly spaced group closer to the center of his range is easier for him to defend against other stallions. The mares likely don’t care at all, and would not be likely to call this “leadership” if asked.17
Harem tending is the stallion business of recruiting a harem and hanging on to the gals once they are recruited. It is a stressful, self-imposed job, in part because cute guys often can be found on the other side of the herd, and the ladies sometimes exercise freedom of assembly. To guard his mares, the stallion puts himself in harm’s way, between the mares and another stallion. If there are no interlopers to contend with, he can busy himself by making big stud piles or urinating where the mares have made deposits. His highest risk job is also potentially the most satisfying: stealing mares from other stallions.
The blue roan stallion (foremost) is harem tending by expressing a posturing behavior and positioning himself between his harem females (several additional females out of the photo to the left) and an intruding male (right). Depending on the persistence and signals of the intruder, this behavior may develop into agonism.18
For the domesticated horse, all is upside down. To prevent unintended mating and any accompanying friction, stallions are made into geldings, and often mares and geldings are separated. Some boarding facilities won’t even take both sexes.
Some studies suggest that dominant animals in a herd may be more influential, but may not be recognized as “leader”. We will look at dominance in a chapter to follow.
1 Image source: https://c1.staticflickr.com/8/7431/11309019454_1e65a0f12b.jpg
2 Parelli, L. “How to Ride Like a Leader”. April, 2005. http://www.parelli.com/how-to-ride-like-a-leader.html
3 Hayes, T. “The Four Reasons a Horse Says ‘No!’” July 2016. http://horsenetwork.com/2016/07/four-reasons-horse-says-no/
4 Goodnight, J. “Notes From Julie: Horse Behavior – Leadership & Nurturing Your Horse’s ‘Try’. August 8, 2014. http://westerndressageassociation.org/the-hitching-post/trainers-loft/notes-from-julie-horse-behavior-leadership-nurturing-your-horses-try/
5 Bourjade, Marie, Bernard Thierry, Martine Hausberger, and Odile Petit. “Is leadership a reliable concept in animals? An empirical study in the horse.” PloS one 10, no. 5 (2015): e0126344.
6 Byrne RW, Whiten A, Henzi SP (1990) Social relationships of mountain baboons: Leadership and affiliation in a non-female-bonded monkey. Am J Primatol. 20: 313–329.; Schaller GE. The mountain gorilla: Ecology and behavior. Oxford: The University of Chicago Press, 1963.; Holekamp KE, Boydston EE, Smale L. Group travel in social carnivores. In: Boinski S, Garber PA, editors. On the move: How and why animals travel in groups. Chicago, US: University of Chicago Press 2000. p. 587–627.; Peterson RO, Jacobs AK, Drummer TD, Mech LD, Smith DW (2002) Leadership behavior in relation to dominance and reproductive status in gray wolves, Canis lupus. Can J Zool. 80: 1405–1412.; Bonanni R, Cafazzo S, Valsecchi P, Natoli E (2010) Effect of affiliative and agonistic relationships on leadership behaviour in free-ranging dogs. Anim Behav 79: 981–991. doi: 10.1016/j.anbehav.2010.02.021; Dumont B, Boissy A, Achard C, Sibbald AM, Erhard HW (2005) Consistency of animal order in spontaneous group movements allows the measurement of leadership in a group of grazing heifers. Appl Anim Behav Sci 95: 55–66. doi: 10.1016/j.applanim.2005.04.005; Réale D, Festa-Bianchet M (2003) Predator-induced natural selection on temperament in bighorn ewes. Anim Behav 65: 463–470. doi: 10.1006/anbe.2003.2100; Reinhardt V (1983) Movement orders and leadership in a semi-wild cattle herd. Behaviour 83: 251–264. doi: 10.1163/156853983X00183; Boinski S, Garber PA. On the move: How and why animals travel in groups. Chicago, US: University of Chicago Press; 2000.
7 Bourjade, Marie, Bernard Thierry, Martine Hausberger, and Odile Petit. “Is leadership a reliable concept in animals? An empirical study in the horse.” PloS one 10, no. 5 (2015): e0126344.
8 Kohanov, Linda. The Power of the herd: A nonpredatory approach to social intelligence, leadership, and innovation. New World Library, 2015.
9 Rashid, Mark. Horses never Lie: the heart of passive leadership. Skyhorse Publishing Inc., 2011. Page 65.
10 Watch a good video of the process here: McDonald, Steve. “Western Canada Geese Take Off—-60p” https://vimeo.com/31289739. And read a good paper on the subject — though I’m not sure that all flocks take off quite this way: Raveling, Dennis G. “Preflight and flight behavior of Canada geese.” The Auk 86, no. 4 (1969): 671-681.
11 Purnell, Jonathan Q., David D. Brandon, Lorne M. Isabelle, D. Lynn Loriaux, and Mary H. Samuels. “Association of 24-hour cortisol production rates, cortisol-binding globulin, and plasma-free cortisol levels with body composition, leptin levels, and aging in adult men and women.” The Journal of Clinical Endocrinology & Metabolism 89, no. 1 (2004): 281-287.
12 Berger, Joel. “Organizational systems and dominance in feral horses in the Grand Canyon.” Behavioral Ecology and Sociobiology 2, no. 2 (1977): 131-146.
13 Stang, D. J. (1975). Effects of “mere exposure” on learning and affect.Journal of Personality and Social psychology, 31(1), 7.
14 Fraser, Lauren May 28, “Be a better leader for your horse – Horse Myth #10” http://goodhorsemanship.ca/leader-for-your-horse-myth-10/
15 Keiper found that herds of ponies on Assateague Island remained in tact after the stallion died (Keiper, R. 1985…), and Klingel found herds of plains zebras remained stable as their stallions switched out. (Klingel, H. 1967…)
16 Waring, G.H., 1983, Horse behavior: Park Ridge, N.J., Noyes Publications, 292 p.
17 image source: Ransom, Jason I., and Brian S. Cade. “Quantifying Equid Behavior–A Research Ethogram for Free-Roaming Feral Horses.” U.S. Geological Survey Techniques and Methods 2-A9, 23 p. (2009) http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1018&context=usgspubs
18 image source: Ransom, Jason I., and Brian S. Cade. “Quantifying Equid Behavior–A Research Ethogram for Free-Roaming Feral Horses.” U.S. Geological Survey Techniques and Methods 2-A9, 23 p. (2009) http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1018&context=usgspubs