Behavior

Chapter 18


Behavior





INTRODUCTION


If we examine statues of humans or horses sculpted in ancient Greece or Rome, it is immediately apparent that their creators were masters of anatomy. Similarly, men with scientific minds have studied physiology for centuries. Thus, anatomy and physiology, basic medical sciences, have a long history. Yet the third basic aspect of living organisms in the animal world, behavior, is a relatively new science. Not until the late nineteenth century did medical scientists like Jung, Freud and Adler begin an analytical study of behavior.


Every living creature has adapted anatomically and physiologically to the habitat in which it has evolved. Its behavior too must adapt to the environment in which it exists. All three adaptations—anatomy, physiology, and behavior—are essential for survival and propagation of any species. All three are genetically predetermined. Thus if an animal enters the world, say a newborn calf, we can accurately predict its anatomic appearance: what it will look like, its approximate size, what its digestive system will be, etc. We can also make accurate predictions regarding its physiology: its normal body temperature, heart rate, gestation period, and so on. Because it is a bovine we can also know how it will behave: its defensive actions, social interactions with other bovines, its courting behavior, its body language of aggression, dominance or submission.


All three characteristics—anatomy, physiology and behavior—are however subject to a certain degree of modification. For example, malnutrition may alter the potential anatomy of an animal. Exercise or living at high altitude may cause physiologic changes. Learning after birth will shape its behavior. The behavior of horses, therefore, is to a great extent programmed prenatally, but from the moment a foal enters this world learning begins.



THE SCIENCE OF BEHAVIOR


The science of behavior is so new that only in recent decades have we begun to understand its complexities. Until the middle of the twentieth century it was widely accepted that animals behaved according to instinct, but human behavior was all learned. Now we know that every newborn animal is endowed with behaviors that are genetically predetermined, and will also acquire behaviors as a result of learned experiences.


The horse, in the wild, is a prey animal, providing a source of food for the large carnivores. The horse evolved in North America, preyed upon by a variety of large felines such as the saber toothed tiger and the cave lion, and a variety of large canines such as the dire wolf. Its primary defense was flight.


Many herbivorous species are equipped with formidable anatomic weapons of defense such as, for example, the horn of the rhinoceros, the tusks of the hippopotamus or wild boar, the horns of a Cape buffalo or musk ox, or bighorn sheep. When threatened, these species lower their heads, charge, and can use their weapons very effectively. The horse, however, is not so equipped. Its defense is to sprint away from perceived danger, and its anatomy and physiology are well equipped for flight. The equine cardiovascular system, musculoskeletal system, respiratory system and senses are those of a flight creature. Because it is dependent upon flight to survive in the world, the horse is uniquely endowed with behavioral characteristics that must be appreciated and respected if we are to get along with this animal.



BEHAVIORAL CHARACTERISTICS


Horses are the most perceptive of all domestic mammals, equipped with hearing, a sense of smell and a tactile sense far exceeding those of humans. Its vision, while inferior to that of humans in color recognition and depth perception (due to the lateral placement of the eyes), is much superior in detecting movement, in night vision, in peripheral vision and in speed of accommodation, which is accomplished by swiftly altering the position of the head.


The reaction time of the horse is the fastest of all domestic mammals. As the horse evolved, those that reacted slowly did not survive to reproduce. The memory of the horse is the best of all domestic animals. Moreover, horses learn faster than any other domestic animal. The slow-learning ancestors of the horse did not survive.


Interestingly, this timid, flighty creature—this ultimate prey—can be more swiftly desensitized to frightening stimuli than other animals. Why? Because flighty species must quickly desensitize to frightening sensory stimuli once they are determined to be harmless, or else they would be running all the time. There would be no time to eat, drink, rest or reproduce. The fact that horses can be quickly and lastingly desensitized to frightening stimuli is one of the main reasons they are so suitable for domestication. In warfare, for hunting, as a draft animal, the horse had to accept endless normally terrifying stimuli.


The horse, one of only a dozen mammalian species which mankind has successfully domesticated, became the most important factor in the spread of cultures and civilizations.



DOMINANCE AND HIERARCHY


Like most domestic animals, with the exception of the cat, the horse is an animal that lives in groups led by a leader, a dominant mare as a rule. Horses, then, readily accept humans as surrogate herd members and as herd leaders. This is why, for thousands of years, horses were so useful to mankind. They worked for humans.


Now, a remarkable change has occurred in the industrialized world—the horse is increasingly becoming a companion animal. Indeed, in many cases, the horse has become a surrogate human: a friend, even a child. An animal that throughout history primarily played the role of a slave, now sometimes becomes the master.


Animals that live in groups have what is called a dominance hierarchy. This hierarchy is established in varying ways, depending upon the species. In horses the dominance hierarchy is established by control of movement. This is a flight species. Horses establish leadership—dominance—by controlling the movement of their peers. This control can be expressed in either of two ways. Movement can be caused by the dominant individual: observe how the lead mare threatens her subordinates, causing them to yield space. Conversely, movement can be inhibited by the dominant individual: observe how a herd sire will drive his harem, then bunch them up and, head swinging from side to side, forbid them to move. Controlling movement of the horse is part of every horsemanship training technique. Properly done it causes the horse to view the human handler as a surrogate leader.


Each species has a body language unique to that species and instinctively understood by members of that species. That language can be learned by other species, just as humans learn to understand the snarl of a dog, the lowered head and pawing of the bovine, or presented hindquarter and elevated hindleg of a horse. A creature that lives in groups may signal surrender by assuming a position of vulnerability for the specific species. The dog, therefore, lies down exposing throat and abdomen to signal, “You are in charge. I won’t question your leadership”. Human beings in every culture bow in submission, exposing the back of the head to mankind’s primary defense, the club. Cattle elevate the nose, and horses, which are most vulnerable when grazing or drinking, lower their heads and make mouth movements to signal submission. Head elevated and lips tightly closed, the horse says “I want to flee”. Head lowered and lips loose or licking and chewing means “I accept you as my leader”.

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Related posts:

  1. Fundamentals of the equine pre-purchase examination
  2. The nervous system
  3. The stallion and mare reproductive system
  4. Perinatology

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Jul 8, 2016 | Posted by in EQUINE MEDICINE | Comments Off on Behavior

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