Among the most remarkable animal stories are those involving friendships where we might not expect them. A friendship between man and dog is not surprising — after all, a dog is man’s best friend. Nor is it surprising to find a friendship between two dogs — or two men. We expect intraspecies friendships (friendships within the same species) .

But then we don’t. A friendship between two fish would surprise us, or between two invertebrates, two amphibians, or two reptiles. And we are surprised when we come upon apparent friendships between two very different species, such as cat and bird or duck and owl.


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”.

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.

Courtship and Reproduction

Stallions are from Mars, Mares are from Venus
’The single most important difference between the sexes is the difference in their investment in offspring. The general truth is this: females do all the investing; males do none of it. Although the general rule has many exceptions, it accurately identifies the primary source of conflict between the sexes: in most sexual organisms, most of the energy and time invested in offspring comes from females. From this basic fact it follows that, for males more than females, reproductive success is limited by the number of matings with fertile partners. For females more than males, on the other hand, reproductive success is limited by the time and effort required to garner and transfer energy to offspring and to protect and care for them. Males therefore are usually more eager than females to mate at any time with any partner who may be fertile, while females are usually more careful than males to choose mates who seem likely to provide good genes, protection, parental care, or resources in addition to gametes. Combined with female interest in mate quality, male interest in mate quantity creates a widespread conflict of interest between the sexes. But I guess you knew that.