During my recent Brazil tour, we were fortunate to see eleven different species of monkeys, which beat my previous personal best for a trip by a wide margin. This was thanks in large part to our time in the southern Amazon, which produced the majority of our primate sightings.
This is the tufted capuchin (thought to be different from the bearded capuchin commonly seen and misidentified in the Pantanal), a juvenile that descended a tree and gave us some clear views. In this case I liked how the curling vines were echoed by the curled tail.
Canon 600mm f/4