Black Howler Monkey, BrazilThis black howler monkey was hanging out in a tree above the flooded grasslands of the Pantanal in Brazil. They are a sexually dimorphic species, meaning the males and females have contrasting coloring. The males (like this guy) are almost uniformly black, while the females and young are mostly golden in color. Nikon D300 with Nikkor 200-400mm lens (at 550 with 1.4 teleconverter) ISO 800, f/5.6 at 1/500th of a second