I asked a question yesterday, and I meant it as a question: why do people do this?
I think we’re getting closer to an answer.
We heard the dog barking again today on our walk. We had food and water. As we got close to the brushy area of the dog, I veered off, hoping — ridiculously — the the six dogs of our entourage might follow. Of course they didn’t, so I went to see what Syd had found.
The dog had been moved. Chained to a different tree, 15-20 meters away.
The big bowl was there, again overturned. Syd rinsed it out and filled it with water, and left a “disposable” (I know…) plastic container with food. The dog barked the whole time. Our dogs were not really a problem. But look at this picture:

Note that I can’t get close enough to get an image of the dog (close in to center, white paws at 1 o’clock), nor Syd, nor Jordan (black dog). In other words, the dog — in addition to being moved — is more hidden.
Of course, the dog totally betrays his position by barking, but he also barks defensively the whole time Syd provides food and water.
So, what to make of this? Mariana the Vet informs that this looks like a temporary arrangement. Family visiting for Easter (sorry, the secular Semana de Turimso — Tourism Week), building a fence, construction, whatever: needing a dog out of the immediate space for a limited amount of time. Not wonderful, but not bad. Not cared for as you or I might like, but not left to die.
Of course, time will tell. But, as I said yesterday, I am not in a rush to judgment. Hopefully, it’s all a non-event: some people parked their dog in the woods — horrible as you might think that — because they needed the dog to not be in their space for a bit.
Ya veremos. With time we will see.
And we will be watching.