Bioacoustics of Presbytis melalophos

Formerly, P. mitrata , P. bicolor , and P. sumatrana were considered subspecies of P. melalophos . There are widespread geographic gradients in color and individual variation (often in the form of wellmarked morphs), making assignment of subspecies difficult. In addition to the typical P. melalophos , there are three main morphs that coexist widely overits distribution. They have been described as “nobilis” (foxy-red), “ferruginea’ (less reddish), and “aurata’ (golden-buff with a black spot on chest, black hands and feet, and a white tail-tip). There is a fourth form described by N. F. Chasen in 1940 with the name fluviatilis. It is found in Palembang, Sumatra, and is similar to the Black-crested Sumatran Langur but much paler. The taxonomic status of these morphsis currently under study. According to genetic and acoustic data, the proposed distribution of P. melalophos may have to be extended into the distribution of P. mitrata . Monotypic.