Ateles geoffreyoi. I think.
Don’t know what those berries are he’s eating–looks like a lot of work for not a lot of payoff. But I get the impression he knew we were watching. Maybe it was all an elaborate ploy.
If those friendly gun-toting dudes I ran into at Tikal were indeed hunters, they were probably looking for this guy. But I guess that’s what you get for crossing the gods: joyful tree-swinging, and a whole lot of maize-beings hankering after a rack of your ribs grilled with chiles and lime.