I recently visited Nyungwe National Park in Rwanda, one of the continent’s most ancient montane rainforests. As you enter the forest from the surrounding tea fields, its acoustics and grandeur are arresting. Not far into the forest, I had the privilege of witnessing a super-troop of over 300 Angolan colobus monkeys. They were crossing the newly resurfaced national highway that cuts through the park. Small groups hurriedly dropped down to the roadside and crossed at intervals between the passing of intimidating ten-ton trucks. It was a tense and bittersweet experience.