We recently brought in a TWH gelding. He is now the only gelding among 6 mares (three are minis, and one is a mini stud, but the minis are kept in a separate less-grassy paddock away from the big horses). Not only did his arrival bring the two younger mares into season, but I am having trouble figuring out which horses "like" him, and therefor which horses to turn him out with.
Here's what happens: Big momma mare just pins her ears back at him when he gets close, but doesn't lunge at him or offer to bite. Just kind of a "I would prefer you stay of there" gesture. I would not be concerned about them being turned out together, because they'd probably just ignore each other. When the gelding was turned out with the 3 other mares (excluding momma), the youngest filly (4 yrs) would chase everyone away from him, or chase him away from everyone else, and she would pair off with him and follow him around a bit, then turn around and rejoin the other 2 mares. The newest mare (5 yrs) was at the bottom of the pecking order when he arrived. They were great at first, flirting and whatnot, but then she started chasing him aggressively all over the paddock.
The gelding's personality is VERYYY submissive. He'll just stand there, let them do their sniffing, and if they pin their ears he'll walk (or run) off. He isn't pushy at all. If someone tries to steal his feed (all they have to do is walk toward him) he won't put up a fight, he'll just walk off. Ohh, if only all men were like that ;)
Soooo, what do you guys think is going on?!!