Champing is most commonly described as a behavior suggesting submission or appeasement. That’s a good intuitive guess, because it’s usually a foal’s response to an older herd mate. Foals sometimes do it toward their own dams, and sometimes it’s directed toward humans, but that’s more common with bottle-raised foals. More often it’s toward a stallion, if there’s one in the group, or any other of the older horses with which the foal lives. Sometimes the foal champs during a sexual behavior encounter between his dam and a stallion.
Champing declines in frequency as the foal gets older and is rare to see after they are 3 or 4 years old. Dr. Ron Keiper (PhD), who spent years with the Assateague ponies, describes it in juvenile males toward the harem stallion, as an aggression-reducing tactic.
However, describing it as only a submissive response is kind of a weak assessment of the behavior. In horses, the most common means of submission and avoiding aggression from another is to just move away. With this champing behavior, the foal does it while approaching or staying right where he is in relation to the more dominant or threatening individual. There might be even close nose-to-nose contact with the other horse. Also, a fair proportion of the time it does not even prevent aggression.
Instead of submission, some have called it more of an appeasement gesture. The posture of head and neck lowered, with the ears erect or out to the side (rather than pinned back) might serve this function. Also, the chewing motion might mimic the action of mutual grooming, which is an affiliative behavior among horses.
Rather than being a visual cue to another horse, champing might be a displacement activity. A displacement behavior is one seen out of context in a given situation. It’s something an animal might do when he is facing a motivational conflict, such as wanting to perform two incompatible behaviors (e.g., approach-avoidance of something frightening), or during times of frustration when given two incompatible signals from a trainer, or during times of social tension. Displacement behaviors are self-directed and believed to be calming or soothing. Some think champing as a displacement behavior might be self-soothing, because it seems to mime mutual grooming, nursing, or grazing—all things that should provide calm and comfort to a horse. And it’s done at a time when the foal might not know if a given individual, ordinarily nonthreatening, might become an aggressor in the current situation.
So champing is a great behavior to talk about. It seems so simple, and we’ve all seen it if we’ve been around foals. But the more you look into it, the more complexity there is!
Courtesy of theHorse.com