The Southern muriqui (Brachyteles arachnoides) is the largest primate in the Americas, only found in the Atlantic Forest, within the Serra do Mar mountain range in the states of Paraná, São Paulo, Rio de Janeiro, and a small area of Minas Gerais. Its population has declined due to forest fragmentation and hunting. The Southern muriqui is a species globally classified as "critically endangered" by the IUCN Red List.
At the beginning of the year, the Muriqui monitoring programme at REGUA/PETP got under way with the active participation of REGUA's staff members Rildo and Gabriel, alongside researchers from Caminho da Mata Atlantica with support from Asa Socioambiental Institute through Projeto Guapiaçu.
The aim of this initiative is to find and map Southern muriqui populations within this territory using active search methods.