The Endangered dryas monkey is one of Africa's most mysterious primates. They are difficult to find because they live in dense vegetation in secondary forest thickets. Using non-invasive research and no-flash camera traps from 2014 to 2019, scientists have confirmed the occurrence of the dryas monkey at seven locations in the Democratic Republic of the Congo spanning a total area of 3,453 square kilometers, based on opportunistic reports provided by local village residents and park patrols.