Wild animals that live in groups — herds, flocks, schools — form friendships. They derive benefit from being together. They don’t relish separation from their extended family.
A band is a family group of one adult stallion, one to three mares, and their foals. A herd can consist of multiple bands, and the connections between bands are weaker than within them, so a herd may show “fission-fusion” as it splits off a band or adds a band. In this book, the distinction does not matter, and I typically use “herd” to refer to a group of horses.
Horses are weird. Horses are unique among ungulates (large hoofed mammals such as rhinos, cattle, pigs, giraffes, camels, deer, and hippopotamus) and even most mammals in building and maintaining long-term bonds. Mares, stallions, and geldings all bond this way, choose to live together, and remain together until separated by fate. Horses have a sophisticated parental care system in which moms, dads, siblings, the peer group and others may play a role in raising foals of both sexes. A band of horses is a matriarchy, with one mare at the top and most of her daughters, regardless of age, and any sons that are below the age of 2. In the wild, feral bands of horses may have one or two stallions with the group, who play a role in defending territory, driving off other stallions, and fathering some darling foals. Herds form from bands, and alliances in the herd transcend family. In both herd and band, all cooperate in various responsibilities, such as predator defense.
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.
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.
Agonistic behavior is a group of social behaviors that relate to fighting. Agonistic behavior may include warnings (threats and displays), efforts to break off an unpleasant encounter (retreats, placation), fighting, and conciliation. Aggression is a subset of agonistic behavior. The word labels hostile or violent behavior, and may include threats of such behavior, but excludes retreats, placation, and conciliation. Aggression is much more common in captive domestic horses than in feral horse bands.2
Aggressiveness is a temperament in which a horse shows hostile or violent behavior toward a human, horse, or other animal. Aggressive horses are more likely to show threat displays under the right circumstances. In contrast, an assertive horse is confident and forceful. An assertive horse might be the first through the gate at feeding time; an aggressive horse might be more likely to bite another horse while waiting at the gate. A horse may be both assertive and aggressive.