According to the literature, ten primate species (Saguinus martinsi (Thomas, 1912), Saguinus midas (Linnaeus, 1758), Aotus trivirgatus (Humboldt, 1811), Saimiri sciureus Linnaeus, 1758, Cebus apella Linnaeus, 1758, Cebus olivaceus Schomburgk, 1848, Pithecia pithecia Linnaeus, 1766, Chiropotes sagulatus Traill, 1821, Ateles paniscus Linnaeus, 1758 and Alouatta macconelli Linnaeus, 1766) have geographic distributions that encompass the study area.
The number of sightings in our study was greater than all "terra firme" sites surveyed by Peres (1997) for the genus Alouatta, Ateles and Chiropotes although less when compared to data from Parry et al.
Also of note were records of what appeared to be two different phenotypes of Chiropotes sagulatus, although this requires further verification.
Support for this comes from our preliminary observations of another form of the genus Chiropotes, and possibly of the genus Pithecia, although proof of this requires the collection of specimens and further morphological and genetic analysis.
In our study, the genus Ateles, Alouatta and Chiropotes presented a greater number of sightings than those presented by Peres (1997) for terra firme sites although greater values for A.
The red-backed saki, Chiropotes sagulatus, the second most abundant species in the study, in terms of direct records, presented the highest group sizes with up to 36 individuals in one observed group.
Our records of species from the genus Pithecia and Chiropotes are examples of these problems.
In order to elucidate these taxonomic discrepancies we recommend further systematic monitoring studies, with collection of some individuals for morphological and genetic analysis, to resolve the taxonomic doubts as to the Chiropotes and Pithecia.
Observacoes sobre a ecologia e o comportamento dos cuxius (Chiropotes albinasus e Chiropotes satanas, Cebidae: Primates).
Habitat Use by Chiropotes satanas utahicki and Syntopic Platyrrhines in Eastern Amazonia.
Large-scale deforestation threatens thousands of species, many of which are already listed as endangered by the Brazilian Government, such as some birds (Dendrexetastes rufigula rufigula Lorenz, 1895, Dendrocincla merula badia Zimmer, 1934, Dendrocincla fuliginosa trumai Sick, 1970, Pyrrhura lepida coerulescens Neumann, 1927, Pyrrhura lepida lepida (Wagler, 1927), Clytoctantes atrogularis Lanyon, Stotoz and Wilard, 1990 and Phlegopsis nigromaculata paraensis Hellmayr, 1904) and primates (Cebus kaapori Queiroz, 1982, Allouatta belzelbul ululata Elliot, 1912 and Chiropotes
satanas Hoffmannsegg, 1807).