This afternoon, I noticed that Pie is beginning to respond to me - if he's in a small paddock he'll come up to the fence to greet me, and if he's out with the geldings, he no longer tries to walk away when I come up to him (which he did the first couple days). He clearly knows who I am, and that I'm his person. He's also getting a bit better about picking up his feet - we'll keep working on that. His leading is now perfect (based on what I want from him) and he's able to easily soften when he backs in hand with a halter.
This afternoon we started working a little bit on his herd-boundness. I was able to use the fact that he ties very well for this. After I got Dawn from the pasture and got her saddled for our ride, I left her cross-tied in the barn and went to get Pie. I took Pie and a hay bag with a flake of hay in it to the arena and tied Pie, with the hay bag in reach, at one end, where he was out of eyesight of the geldings. Then I went and bridled Dawn and brought her out. Pie called once when Dawn and I were out of sight in the barn - I stuck my head out the door and told him we'd be right out.
Dawn was somewhat taken aback by Pie's presence in the arena. But she was very good about it, although very distracted by him anytime we passed nearby. We worked on our softening work at the walk and trot - this is the first real work session we've had in almost two weeks. Every time we got near his end of the arena, she would prick her ears and focus on him. Sometimes with other horses she knows she pins her ears and makes faces, but with him, perhaps because they haven't formally met, she was more interested than annoyed.
Pie spent some time trying to stretch down to reach bits of grass (out of reach), fidgeting from side to side, and pawing (only once), and settled down to eat hay, eventually with a leg cocked. He even peed when he needed to. By the end of Dawn's work session - we got very nice relaxation at the walk, including walking by a downed section of arena fence (due to the high winds last week) without concern, and less good relaxation at the trot, although not so bad for a horse that hasn't trotted under saddle in so long - he was calmly eating hay with one hind leg cocked.
Tomorrow the weather's supposed to be even nicer, so more horse work ahead!