Density and habitat use of primates at an Atlantic forest reserve of southeastern Brazil.

About 58.3 km of transects were surveyed throughout 21,800 ha of an Atlantic forest reserve of southeastern Brazil, yielding habitat preference data and density estimates for three of the four primate species present. The densities were calculated using the "Fourier Series Estimator" and were 10.5, 2.2 and 1.2 groups/km2 for Callithrix geoffroyi, Cebus apella robustus and Callicebus personatus personatus, respectively. Alouatta fusca fusca although present, was not seen during the survey. C. geoffroyi was spotted predominantly in the low strata of secondary forests while C. a. robustus preferred the higher strata of primary forests. The encounters with C. p. personatus were rarer but the species seems to occur in the middle strata of both primary and secondary forests. Local populations were estimated at 1644, 344 and 181 groups for these three species, respectively. With the exception of A. f. fusca which seems to occur at extremely low numbers, the densities for the other species are within the range of reported values for other species of these genera.