Spatial distribution and habitat suitability of Boutourlini’s blue monkey (Cercopithecus mitis boutourlinii Giglioli, 1887) in Ethiopia: A Maxent approach

Species distribution models capture species’ ecological niches and can be used to infer the distribution of suitable habitats for species of interest. Boutourlini’s blue monkey is suspected to have undergone a population reduction of thirty percent over the last forty years, with declining habitat quality, extent of occurrence, and area of occupancy due to various anthropogenic activities. This requires an understanding of the relationships among species in response to environmental variations. The objective of this study was to assess the current and future suitable habitats of Boutourlini blue monkeys via maximum entropy modeling (Maxent) to conserve the species in Ethiopia. Seventy-one occurrence points were recorded between 2023 and 2024, and 10 environmental variables were processed via geographic information systems and species distribution modeling tools. The study revealed that annual precipitation was the most important bioclimatic variable, with a 63.6% contribution, followed by precipitation in the driest month and the annual mean temperature, with contributions of 13.8% and 6.8%, respectively. Under current conditions, areas identified as suitable habitats for Boutourlini’s blue monkey are estimated at 119303.50 square kilometers across Ethiopia. The habitat suitability models indicated an overall increase in the suitable habitats of the species under all future climate scenarios for the years 2050 and 2070. However, the projected suitable habitat distribution shifted and fragmented. In the present study, the generated models provide important information for the conservation and management of Boutourlini’s blue monkey. Moreover, intensive work on fragmented forests, assessments of population status, and conservation challenges are recommended to address the impacts of climate change through either mitigation or adaptation measures.