White-faced Capuchin

The white-faced capuchin is the rainforest's problem-solver, a three-kilogram primate with a prefrontal agenda. Troops of ten to thirty sweep through Costa Rican forest like an audit, turning leaves, cracking branches, unrolling bark, testing everything with hands that are nearly as clever as the brain behind them. Capuchins use tools, rub themselves with citrus and pepper plants as insect repellent, and maintain politics complicated enough that primatologists build careers on single troops. They live long, sometimes past 40, and they remember. In parks like Manuel Antonio they have also learned that tourists mean bags, and bags mean food, a lesson that took them approximately one afternoon.