The question was already in mind by the time I set my canoe into the water.
"What is the minimum space required for a spirit to survive?"
I set out from the North Cove in Essex, waded the gap into the big river because it was just past low tide and the water was not more than 2 inches deep at that point, and headed up and across. I soon noticed that I was being sped along in a great eddy - not one of those dramatic swirls of whitewater, but one that was fast and smooth, something you would not notice from shore, something of the big river. In fact, I did not see it until I was in it. It lasted two or three hundred yards.
I'm no expert on spirit things. My experience is thin... I've had a spirit animal dream, which came after many consecutive days of canoeing. Meaningful as it was, it was still a dream. Weirder, much weirder, was my run in with a forest tree spirit. And, this makes me sound insane. It was unexpected and came after many frequent off trail hikes in a rugged cedar forest. I saw nothing, I heard nothing, but I was distinctly told to leave the area - that I did not belong where I was standing. I left. I imagine that it will never happen again during my lifetime.
I don't think that anyone has ever seen any of the land spirits. I don't believe anyone ever saw a sasquatch, or a dzunukwa, or a Norwegian huldre. I do believe that people sensed them, or sensed something. These are spirits of big wild places where people disappear, where people are much much smaller than the world they live in. (City people don't have spirits, they have characters.)
Common mergansers are flocking and red wing blackbirds have returned to the marshes. I am finding a good number of bird nests from last summer - the taller brush is down and the random woven structures easy to spot in the taller shrubs.
So, how much space does a spirit require? What is space? This is not really a conversation of yards and feet. It's a spiritual world and "space" goes well beyond our measurable quantities.
I believe that the land will only speak to one who is open and completely prepared to hear. Space is probably different for different people, but I would guess that anything that takes one's attention away from where they are is an intrusion into the space...road noise, airplanes, cell phone, gps device, hiking partner, plant guidebook, camera, work stress, etc. The closer you are to being one with the land, the closer you are to.... something you don't understand.