How close would an “intruder” have to approach before the dog reacts? Is it asking too much for hiker/bikers to stay 100 yards away from a flock of sheep?
A hundred yards? In open timber you could walk right into a herd of sheep and probably not know it - it just depends on how spread out they are.
Got me on that.. Don’t know.
However, I think it would vary, depending on the individual dog, the size of the herd, the terrain, the extent of the scattering of the herd at the time, the actions/behavior of the threat approaching, etc. There is no cut/dried formula here. Dogs are very contextual in their behavior, and generally will not react to the same threat (i.e. coyotes) similarly in different circumstances, much less a different threat in similar circumstances.
In most cases, I suspect the proper behavior is to stay a reasonable distance away (i.e. where you don’t provoke a response from the dog) from the herd, ignore the herd (i.e. don’t stop, approach, take photos, try to pet the sheep, etc.) and just move on. I would treat them as someone else’s property, and just stay away.