Yes for the S+ hitching post; sorry couldn't remember what exactly it was called. Outside of building a fence, do you know a way to keep them in a general area without the post so they can defend themselves? Can they breed while they are hitched up? I thought they had to be able to move around.
when you attach them to the hitching post and put them on wander they will breed as long as they are in range.
If what you want is to define a wander area that they will operate in and defend, then yes building a fence, or using the leash that was added in extinction.