The White-faced saki is a monkey from South America.
Both pictures show male white-faced sakis, I could not get any pictures of a female one which has a greyish coat. White-faced sakis tend to mate for life in captivity but are somewhat less strict in this sense in the wild. They live in the understory of the forest canopy and eat fruits, nuts, and insects.
The white-faced saki is doing well in the wild. Zoos seem to like to keep white-faced sakis because they are interesting creatures and delightful to look at.