OK, a tiny fraction of a howler monkey peering out. Getting close to these guys without getting beaned with coconuts (or worse) is reportedly tough.
This is the kind of animal where you can get a shot. There are plenty of these guys around the jungles. It just takes more time and a better camera setup than I had. I would have loved to have had a boat to myself, no schedule, and better gear.
Here's a better look at one of these noisy beasts.
http://www.grete-david.co.uk/mediac/400_0/media/DIR_157569/Black~howler~monkey.jpg 
