White-cheeked macaque (Macaca leucogenys): A new macaque species from Medog, southeastern Tibet.

We describe a newly discovered Macaca species from the Medog, in southeastern Tibet, China, Macaca leucogenys sp. nov or the "white-cheeked macaque". Based on 738 photos taken during direct observations and captured by camera traps this new species appears to be distinct from the Macaca sinica species group. Moreover, the species is distinguished from all potential sympatric macaque species (M. mulatta, M. thibetana, M. assamensis, and M. munzala) in exhibiting a suite of pelage characteristics including relatively uniform dorsal hair pattern, hairy ventral pelage, relative hairless short tail, prominent pale to white side- and chin-whiskers creating a white cheek and round facial appearance, dark facial skin on the muzzle, long and thick hairs on its neck, and a round rather than arrow-shaped male genitalia. This new macaque species was found to exploit a diverse set of habitat types from tropical forest at 1395 m, to primary and secondary evergreen broad-leaved forest at 2000 m, as well as mixed broadleaf-conifer forest at 2700 m. Its range may extend to neighboring counties in Tibet and the part of southeastern Tibet controlled by India. The white-cheeked macaque is threatened by illegal hunting and the construction of hydropower stations. Discovery of this new primate species further highlights the high value for biodiversity conservation of southeastern Tibet and calls for more intensive surveys, studies, and environmental protection in this area.