Here we present 192 new records of 22 species and subspecies of primates, collected in 56 different localities during 10 field expeditions across the arc of deforestation between 2015 and 2018. Based on such new records, we extend the ranges of Alouatta puruensis, Ateles chamek, and Saimiri collinsi; identify potential hybridization zones in Alouatta and Ateles species; redefine the range of Plecturocebus moloch; and clarify the ranges of P. baptista and P. hoffmannsi.

Reports of male dominance in greater bamboo lemurs were not supported by data. We studied agonistic behavior in one captive group and could confirm this assertion, which sets this species apart from all other group-living lemurs.