Why are equines the only grazing animal which seemingly enjoys chasing and dominating other grazing animals? This is a question which has baffled me for years (actually decades) yet it is an important aspect of animal behavior that people seem to miss. I bring this up because of a recent discussion on bison.
I know there are a lot of people out there who are going to counter with “My bison charge anyone on horseback,” but the simple fact is, they aren't. If they were, cutting horse trainers would not risk using bison to tune up show horses worth tens, if not hundreds of thousand of dollars. So why does a herd of bison “charge” people who are horseback? Curiosity.
When confronted with something new, grazing animals are generally either afraid or curious. If they are afraid, they will watch cautiously or flee. If they are curious they will go see what it is. If one or two of a group of grazing animals get curious about something and start running towards it, the whole herd will follow.
In the case of a horseman being “charged” by a bison herd, it is a case of a few of the animals being curious enough about something to run over to check it. The rest of the herd follows. The first thing that pops into the rider's mind is panic, which transfers immediately to the horse. Horse and rider vacate the premises with the bison following trying to see what the heck that strange thing is.
Cattle will do the same thing. A person walking across a field full of yearling heifers who are not used to seeing a person afoot, will come stampeding right up to the person and if the person runs, they will keep following. If the person stops, so do the heifers, but they may come close enough to them to sniff them.
Once I had a steer in a little group of five hundred that was insanely curious about rabbits. One morning all five hundred were running around the pivot, as a herd. I could see noting they were chasing so I rode to that pivot to check it out. When I got there they were all stopped in a big circle. When I got to the middle, the one steer was standing on a jack rabbit's leg while he was licking it. Other than standing on a leg to pin it down the steer was not doing anything aggressive towards the rabbit. On the contrary, he was grooming it!
This was not a one time affair with this steer. In the several months I had this group of cattle, I had to move them back and forth across some desert ground to some remote pivots. This steer was naturally in the lead, and whenever a rabbit jumped up in front of him, he'd take off chasing the rabbit.
There is a similarity between the rabbits being chased by that steer, and riders being chased by bison. Instead of thinking about what was really going on, they both ran like heck to get out of the way. All the bison are wanting to do is check you out, and all that steer was wanting to do was give the rabbit a bath.
The point to all of this is that bison can be worked horseback. You have to put some thought into it and acclimate them first. After all, if bison choused horses, Indians would have ridden bison and lived in horse hide teepee.