An animal called a woolly monkey seems like it should live in the frozen north, not the sweltering Amazon Basin. But the thick coat of fur covering these large primates protects them from the sun, rain, and insect bites of their native habitats in the forests and cloud forests of Peru, Columbia, Ecuador, Bolivia, and Brazil.

Woolly monkeys were once considered four species: the gray, Columbian, silvery, and Peruvian yellow-tailed woolly monkeys. More recent genetic studies suggest there are only two species—the Peruvian yellow-tailed and the common (or brown) woolly monkey. The gray, Columbian, and silvery woolly monkeys were reclassified as subspecies of the brown woolly monkey.

The coloring of their coats is the main difference between