Black howler monkeys are found in parts of Bolivia, Paraguay, Argentina and Brazil. There are many Howler monkey species that range throughout Central and South America, but these are the ones usually found the furthest south.
As for their colour, only fully mature, adult males are black in colour. Younger Black howler monkeys, and females have a black and gold colour combination.
This howler monkey was photographed in the Pantanal region of Brazil.