Mentawai langur

The Mentawai langur, Presbytis potenziani, is a primate of the family Cercopithecidae that is endemic to the Mentawai Islands of Indonesia, where it lives on Sipora, North Pagai and South Pagai in primary and secondary forest dominated by dipterocarps. The Siberut langur was formerly treated as one of its subspecies. Infants are born white, and over two to three weeks the coat begins to darken from the dorsal midline and head; by three months the animal is jet black with a dark reddish-brown belly and chest and white on the throat, cheeks, forehead and tail tip. Males are told from females by a white patch of fur around the genitals. The body is slender and the hind limbs are longer than the forelimbs. Groups travel about 540 metres a day, move by quadrupedal running, climbing and leaping, sleep high in the canopy above 20 metres, and have home ranges of 11 to 40 hectares. The diet is mostly leaves, fruit and seed. It is listed as Critically Endangered on the IUCN Red List; its population is estimated to have fallen by 80 percent over the 36 years before 2021, mainly through hunting for food and the loss of habitat to agriculture.