Horses are social animals. They like each other. They like being together.
Well, that’s the simple version.
The more complex, and more accurate, version is that horses like some horses more than others, and they dislike some horses more than others as well. How do they show that preference? By walking up to each other and staying close, mainly, according to a new study presented at the 14th Conference of the International Society for Equitation Science (ISES) in Rome, Italy.
“Many previous studies focus on social grooming, but in our research we’ve found that actually, horses groom each other rather infrequently,” said Konstanze Krueger, PhD, of the University of Regensburg, in Germany. “It would take many hours of observation to gather enough data about social grooming, and that’s impractical in our experience. We wanted to propose a consensus providing the most reliable way to observe social bonds, which is both easy and fast to observe, for both scientists and the public.”
For Krueger and her research team, a far more frequent horse behaviour indicating social bonds is the simple act of one horse approaching another horse and then choosing to stay within about a length or two of that horse for at least a few minutes. That, combined with spatial proximity in general (how closely horses stand close together), can give very useful information about how much horses ‘like’ each other, she said.
While scientists avoid using the word ‘friendship’ (because it is anthropomorphic), in equine groups, they do recognize the social bonds that horses and other equids create, Krueger explained. What’s more, they know that they develop clear preferences for certain individuals within those social bonds.
As handlers, then, it’s up to us to help respect those preferences as we group horses together in a field, she said. For their health (fewer injuries due to conflict) and their welfare (less stress, more peaceful environment), we should aim to group according to the social bonds our horses build. The real trick, though, is knowing how to recognize those bonds, consistently, efficiently, and accurately—meaning, without spending hours upon hours in our horses’ fields.
To test a new parameter of social bonds—that of the ‘friendly approach’—Krueger and her fellow researchers performed non-stop observation on 11 groups of feral horses (Przewalski groups and managed groups of feral domestic horses) for 15 hours a day, three days in a single week. For the 146 horses involved in the study, they recorded mutual grooming, friendly approaches, and spatial proximity. They also noted sex, ranking, aggressive behaviour, groups, group compositions, and group sizes.
They found that all three horse behaviours—mutual grooming, friendly approaches, and spatial proximity—gave reliable information about social bonds, Krueger said. However, mutual grooming was relatively rare and would be easy to miss in a short time frame, making the other two horse behaviours more practical for welfare assessments.
As a side note, they also noted that male horses were more likely to show social behaviours. And in general, horses showed fewer social behaviours as group size increased, she said.
Social bond research gives somewhat varying results from one research center to another, with individual research groups finding more or less significance for some behaviours than others. However, many factors could influence those results, according to Krueger. “Behaviours may differ between horse groups, but they may also differ depending on daytime, season, housing conditions, training, and many other aspects,” she explained. Ideally, scientists should aim to observe as many equine groups as possible under all kinds of circumstances—but this is rarely possible for individual research groups, she said.
“This is why we tried to reach a consensus with our research project,” said Krueger.
While mutual grooming continues to be a strong indicator of social bonds, owners shouldn’t necessarily be concerned if they don’t see this behaviour very often in their pastures, according to Krueger. It’s simply infrequent and could be easy to miss.
Instead, owners and farm managers can focus on observing friendly approaches and spatial proximity to determine social bonds. “The most reliable behaviours still appear to be grooming and friendly approaches,” she said. “But people may also simply observe who is close to whom, most of the time. Closeness also indicates ‘friendship.’”