The Amazon marmosets are poorly known and severely threatened – endemic to the arc of deforestation in southern Amazonia. Based on data from field expeditions across this global deforestation frontier, we provide new records and extend the range of Mico chrysoleucos, provide new records and refine the range of M. acariensis, report the first records of a species of Mico on permanently flooded forests, and hypothesize the existence of a hybrid zone of these two species and also M. melanurus.

Despite many explorations and surveys, the geographic distribution of many primate species, particularly in the neotropics, is not yet well known. In this paper, we provide evidence that extends the range of Spix's saddle-back tamarin in Peru.

Baboons occur in a large range of different habitats. However, data on the ecology of Guinea baboons were scarce. We provide information on the ranging behaviour, habitat use, and diet of a population of Guinea baboons in the Niokolo-Koba National Park, Senegal. Home ranges were about 25 km², and they moved up to 13 km per day. They seem to prefer the more forested parts of their home range near the river. Fruit dominates their diet, and the nuts of the palmyra palm are a year-round food source.