Encounter some of the most rare and endangered monkeys on Earth in the Zoo’s Lost Forest. An elevated walkway called Monkey Trails takes you directly through the tree canopy, where you can observe them from two perspectives: tree-branch or ground level. Look for lesser spot-nosed monkeys, a lively troop of capuchin monkeys, colobus monkeys and northern black-crested mangabeys sharing an exhibit, and Wolf’s monkeys hanging out with their friends, the pygmy hippos. Red-tailed and Allen’s swamp monkeys live with spotted-necked otters along Hippo Trail, while just across the path, you’ll find these three species alongside red river hogs and a forest buffalo. There’s never a dull moment in these mixed-species groups! In addition, you'll find vervet monkeys in the Zoo's new Conrad Prebys Africa Rocks. Squirrel monkeys live in the Children’s Zoo. Did you know? Burping is a friendly social gesture among leaf-eating colobus monkeys. Their chambered stomachs digest leaves by bacterial fermentation, which produces lots of gas.