Herd Aggression

From mugwump chronicles
http://mugwumpchronicles.blogspot.com/2009/01/herd-aggression.html

Jonas said>> I have a question about my mare. She doesn't go into heat often, though people do say she is “mareish”. She has a terrible attitude towards other horses.
She likes having a herd, but she hates other horses. She charges through the fence at them and throws up a ruckus if I give other horses attention.
She acts bossy with people, too. She struck at me once, I backed her down the driveway, which is quite long and she is respectful with me. But she still is crazy when it comes to other horses. She also seems to have an influence on other horses, after they are kept with her they lose all their manners and are aggressive toward other horses.
She never used to be like this. I don't understand why she is so "mareish" now. It's all the time and she has no respect for anyone but me.
So if you have any suggestions on how to deal with her behavioral/jealousy issues, I'd love to hear them.<<

And people think studs are tough! In a natural herd situation there is always the “boss” mare. Sometimes they’re called the “alpha” mare or the “bell” mare.

The boss mare is vital to the survival of the herd. She will tell the herd where to go, when to eat and drink, when to run, in general tell them what to do all the time. She gets to decide when to accept a new herd member or when to run somebody off. In exchange for this privilege she gets to eat the best grass, drink the freshest water and live in the middle of the herd where it’s safest. Her babies get the privilege of her status, so they grow up safe and strong.
This is a coveted position in the herd. The way horses work is the boss mare stays in charge, her second-in-command (and favorite herd buddy) gets to help her boss the other horses around, then there’s third, fourth and so on down to the last sorry little horse that’s the bottom of the heap.

The boss mare is savvy and aggressive. She becomes boss by beating the crap out of everybody beneath her. It’s vital to the safety of the herd.

Jonas, I’m sorry, but you have a boss mare. Unfortunately she is not in a natural setting. She can’t get at the horses on the other side of the fence to prove her dominance. She feels they are a threat to her herd, even if her herd consists of you and a goat. So she lives in perpetual agitation, thinking she has to resolve the situation.

You can’t change who she is. You can change her understanding of how she should behave.
You already have made a good start by making her respect you. If I was in this situation I would want to take it a step farther. I would want my mare to understand she can’t behave aggressively towards other horses when I’m around. I would regularly go out into the pasture and drive my mare away from the rest of the herd. I’d do this by swinging a lead rope at her haunches until she skittered off. If I had to whack her a few times I would. If I had to really thump on her I would. I would do this over and over until she understood I had sent her away. Eventually she would stand away from the group, staring at me with her ears pricked. She would probably look sad and confused, but I’d stay tough and ignore her crybaby little self. I would pet the other horses. I would stand in the middle of the group and make her stay out.

Eventually my aggressive mare will begin to graze and act like she’s ignoring me. Then I would relax and let her wander back into the group.

What would happen is I would shift the dynamics of the herd. The other horses would understand I can drive the boss mare away. They would understand I was her boss. She would quit trying to attack them while I was out there.

When I had this mare out to ride or anywhere she is under my control I would discipline her for aggression towards other horses as if she was being aggressive towards me. I would be fair and consistent, but I would make sure she understood I am the one in charge.

You can’t change who your mare is, but you can change how she treats horses around you. She will still be boss mare when you aren’t there, but once a mare proves her dominance things usually settle down.
I hope this helps. Be careful, be firm.