1. Population survey outside IUCN-recognized distribution area: use a drone equipped with thermal camera to survey more efficiently larger and challenging areas (e.g., steep hills, dense vegetation), and linear transect, to assess the occurrence and demography of A. g. guariba in South Bahia. More primates can be recorded during this objective. 2. Assess A. g. guariba genetic diversity in South Bahia: Use fresh fecal samples collected during fieldwork to obtain population microsatellites, haplotypes, inbreeding and population structure. The objectives of this project are related to the National Action Plan for the Atlantic Forest Primates, which highlight the need of studies for surveying remaining populations, especially in south-central Bahia, and research on taxonomy, genetics, demography, and population dynamics. For that, we will prioritize obtaining basic data on the presence or absence in forest fragments, demography, and genetics of A. g. guariba on the North bank of Pardo River, South Bahia. To achieve these goals, our team includes a diverse group of professionals—students, researchers, and professors—working in the fields of ecology, genetics, and veterinary science. The team also includes former presidents of the Brazilian Society of Primatologists and members of the IUCN Primate Specialist Group for Brazil and the Guianas.