Estimating primate densities using home range and line transect methods: A comparative test with the black colobus monkeyColobus satanas

Abstract
The line transect method is one of the main methods used to estimate primate densities. Several protocols have been proposed to analyze the data recorded under this method but none of them have been widely accepted since there is a considerable controversy about their respective accuracy. In this study, densities of the black colobus monkeyColobus satanas calculated using eight different protocols were compared with the actual density given by the home range method. Rates of polyspecific associations were also compared. The two most accurate estimates of group density (under- or overestimation n=23), this did not allow to identify a sharp detection distance. Rates of polyspecific association found with the two methods were similar. We recommend to investigate the influence of the topography for bias in density estimates when using the line transect method.