I feel tremblors all the time that nobody else seems to notice....and confirmed in the news broadcasts later in the day.
My eyes are bad, and my hearing, impaired; but a walk in the woods with company, and I'm the one pointing out the birds and flowers and animals. I see and hear...and especially smell things.....that others don't click on. I think it's cuz folks are having internal dialogue, and missing subtle clues all around them. Animals don't have chats with themselves in their heads. Survival depends on analysis of environment.
My theory is that one can train one's self to a hightened state of permanent alertness. I spent many years on a walking beat in the city....wee hours, totally outwardly focused, looking, listening, smelling, making sub-conscious notes. It becomes a mode after a while. I think soldiers must get this happening, too. Fishermen get it: survival, in all three examples, depends on analysis of environment.
I agree only you left out hunters. I have many times smelled my quarry before sighting them, my broother still thinks I am making this up. On another note about animal sith sense. Most seem to be posting about animals other senses and I indeed believe that these basic senses 9 times out of 10 is what enables the animal to survive. It is just a higher level of sense. Wheteher we are talking about a Deers ability to see movement at great distance or a Turkeys ability to pinpoint your location from a single cluck on the call.
The ability for the animals to see or hear the coing waves or the initial quake I would argue would not be part of the 6th sense that I believe they have.
Their sixth sense comes in, most of the time in my experience as a sportsman, when you are in the field with out a gun and just observing nature you can walk right up on them and they will not spook. But put a gun in your hand and try it. I read once where the vibe if you could call it that, put out by predators is picked up by animals of prey and acted upon. You can believe this or not as I have no way of proving it other than field experience that could be subject to many other factors.