It's a plastic bag.

lol, to be honest, the first thing I thought was that the angle of the shot and the height of the trees left us looking about
20+ feet into the sides of the trees. Just from the photo I would say that this is just a gap in the trees, and not something standing on the ground,
which would seem to be much lower than the object in question.
Now with that said, I will have to take your word for it that you are aware of the area, and in fact are certain that this is something ground-level.
Are you certain, or did you just snap a random photo in a random place? I am not doubting you by the way, just exploring possibilities.
So if this is indeed something on the ground that is walking, so is in fact an animal, in my opinion it can be only one of two things: a bear or a
bigfoot. It obviously doesn't look like a bear, and the coloration is very similar to a silverback gorilla.
So if you are certain that the height and angle of the photo are correct, and this is something walking on the ground, I would conclude that this is
in fact a primate of some sort. That's just my opinion, but I believe it to be well founded as long as the other variables are accounted for.