In 2012, a new monkey species, Cercopithecus lomamiensis (lesula), was discovered in the Central Congo basin. Lesula is a semi-terrestrial rainforest guenon endemic to the area. Using a systematic grid approach, three terrestrial camera trap surveys (two inside the Lomami National Park; one in the buffer zone) were conducted over three years to capture the cryptic species. The objectives of my study were to expand knowledge on the behavioral ecology of lesula and evaluate lesula’s sensitivity to hunting threats. The main findings from my study included: confirmation of terrestriality and diurnality, births clustering during the wet season, social group living of one male and multiple females, and high impact of hunting on group size. By studying the latest added species to the Cercopithecini tribe, my thesis helps to better understand the ecological diversity occurring within this radiation of African primates and contributes to the species’ long-term conservation efforts. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection