I spent some time this morning trying to figure out what was actually doing on with the herd dynamics in our gelding herd, where Drift is chasing Pie. Part of the issue with our herds is that they're very small - 3 mares in one herd and 4 geldings in another herd. Numbers that small can be very problematic when horses leave or join a herd - the dynamics tend to work better when the numbers are larger.
Before Drift arrived at the end of March, Pie and Scout were best buddies. At that time, Fred was still with us, and he and Fritz were a tight pair. When Drift came into the herd, he clearly and immediately established his alpha status - Fritz was a pretty weak alpha before that - but all the horses hung out together, although Fred, who was very feeble, did get picked on a bit, mostly by Scout. Scout and Pie continued to be buddies.
Later that spring, Pie had to come out of the pasture due to a bout of mild laminitis, and we had a very wet spring which meant he couldn't go back out until things dried out. When he went back out with the gelding herd, Drift started chasing him, particularly when Scout's owner came to take him out of the pasture and feed him mid-morning. I wanted to see if I could figure out what was going on.
I don't generally interfere in pasture herd behavior - there's really no point in trying to keep the horses from doing what they're doing. But I am willing to manipulate things a bit to see what happens. This morning, I put Drift in a separate pasture and turned Pie out with Scout and Fritz. Pie hung out with them and was grazing pretty close to Scout. Then, a couple of hours later, I turned Drift out. He quickly galloped off to where the others were grazing (some of these photos were taken into the sun and are greatly enlarged, so apologies for the quality, but they show the dynamics) - that's Fritz to the right and Scout and Pie are out of the frame to the left:
Then Drift started chasing Pie away from Scout - that's Pie on the left and Drift on the right and Scout's out of the frame to the left:
Pie took evasive and self-protective action and headed off to another part of the pasture - that's Pie kicking out, Drift to the right and Scout's unconcerned face at the far left inside the (intruding) post:
Drift said that Scout was all his, and kept a good eye on Pie:
Pie continued to graze by himself, probably 50 yards off, but kept an ear on Drift:
When Scout's owner came to get him out of the pasture, all the horses - mares and geldings both - came to the gates. I expect this has been happening every morning. Drift was in the corner near the gate with "his" mares:
Pie was at the gate, wanting out:
Pie yawned a few times, I expect to release some tension:
Drift kept an eye on Pie, but didn't do anything else - the gate Pie was standing by is not far from where Drift was camped out close to the mares:
Pie greeted Fritz - that's Pie on the left and Fritz on the right:
Drift wasn't too sure he liked this, but didn't do anything aggressive except stare at Pie - that's Drift to the left and Fritz to the right, and Pie's out of the frame to the right:
Now Pie demanded to come out of the pasture:
So then I did something a bit counterintuitive - I took Pie out, put him a separate one-acre pasture and then put Drift in with him. Drift doesn't seem to have a problem with Pie except when Pie interacts with other horses. So I took away the other horses - my hope is that Drift can come to accept Pie as a result of spending time with him, and than perhaps they may even become a pair as often happens with two horses that spend a lot of time together. When I came to get Pie about an hour later, he was as close to the barn and as far away from Drift as he could get - I don't think Drift had chased him as he wan't breathing hard or sweaty, but he was certainly happy to get away from him. I don't know yet whether I'll continue to put Pie and Drift out together with the herd or not right now - I'll have to think about that one . . .