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Dominance and Hierarchy

I have argued that a herd of horses is much like a school of fish or flock of birds, leaderless and choosing a course of action via collective decision making. I have argued that “respect” as is normally meant by humans, does not exist in the horse, and that humans often use it as a euphemism for “fear”. I do not dispute the existence of “dominance” in a herd of horses, but I have questions about what it is and whether the concept is useful. Thirty years ago, researchers were far from a consensus on how to define and measure dominance, and little has changed since then. Anything gets harder to talk about when we can’t agree on what it is.

Rolling

Horses roll. They do so in places where others roll. Eventually, the area where they roll may lose its vegetation and become dusty. What we can’t see is what they smell. Before a horse rolls, he sniffs the wallow. During the roll, he rubs the dust into his fur, and his scent into the remaining dust. He acquires the scent of the herd, and the next horses to roll acquire his scent.

A horse with normal withers will usually lie down on one side, rub against the ground, then roll to the other side and repeat. A horse with high withers may need to stand after the first side, and lie down on the other to complete the job.

The Mind of Your Horse

The brains of mammals are very similar, and differ in degree rather than kind.

The human desire to believe that we are the most intelligent species has led to a number of comparisons of brains. Brain size must matter, but our brains are smaller than those of the elephant or whale. Some researchers find pleasure in noting that some parts of our brain are much bigger than the same parts in other animals. For instance, our friend Cowboy Bob reports that “the brain cavity of a horse is filled with a lot more than what we usually think of as the “brain.” Although the space would, in fact, hold a small grapefruit, the cerebral hemisphere — or “thinking” portion of the brain cavity is a lot smaller.”

If horses could talk, though, they might point out that the brain cavity of their skulls is about the size of ours, and that lots of preprocessing happens between the nostrils and the brain, and between the eyes and the brain. If we compare head size of Mr. Horse and Mr. Man, Mr. Horse does just fine.

Early Learning and Imprinting

Early research focused on the following reaction of precocial birds, something that is now called “filial imprinting”. Filial imprinting is useful in fostering a mother-offspring bond, and makes perfect sense. Even if a bird could learn to follow a man in boots or follow a toy train, in nearly every case the big moving thing nearby is mom, and learning to follow her is a key to survival. We can be comfortable believing that such a feat did not originate with birds, but that young dinosaurs of many species might have also followed their moms.

Filial imprinting seems to have been found in every species of bird that has been studied. We are all familiar with pictures of ducklings following a human or a dog that they have imprinted on. Whether filial imprinting occurs in other species is an open question. While there is a huge amount of early learning in mammals, it is not clear that any of this learning should be called “imprinting.” While the general public is comfortable with the word “imprinting” when talking about young mammals such as foals, scientists don’t use the term. Scientists don’t use the term “imprinting” when discussing mammals because mammals don’t imprint the way birds do. I don’t think it is appropriate to talk about imprinting in horses, but I’ll need to account for the positive effects of early exposure, so keep reading.

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