Presbytis potenziani

Conservation: CITES – Appendix I; U. S. ESA – Threatened; IUCN – Vulnerable as P. p. potenziani and P. p. siberu.

Sumber: Order Primates

Distribution: Mentawai Isls (Indonesia).

Sumber: Order Primates

PROTECTED STATUS: CITES - Appendix I and U. S. ESA - Threatened.

Sumber: Order Primates

Habitat. Primary and secondary lowland evergreen rainforest, swamps, logged forest, and (possibly) mangrove forest and cultivated areas. Mentawai forests are ever-wet rainforests, and annual rainfall is up to 4000 mm. Mentawai Langurs use all levels of the forest canopy, even occasionally coming to the ground, but they spend most of their active time in the middle canopy and resting time in the upper canopy. They are most abundant in forest logged 20 years ago and least abundant in recently logged forest.

Sumber: Cercopithecidae

Movements, Home range and Social organization. On North Pagai, home ranges of the Mentawai Langur are 17 - 40 ha. Social organization is variable; Mentawai Langurs have been observed in unimale — unifemale, unimale — multifemale groups, and multimale-multifemale groups. In areas with high densities and smaller home ranges, males defend territories from other groups, using visual displays and loud vocalizations, sometimes accompanied by adult females in duets. In areas with larger home ranges, adjacent territories may overlap, and groups tolerate each other. Adult males and sometimes females also give loud vocalizations to warn others of predators (people and pythons). Larger group sizes of Mentawai Langurs (compared with the closely related Siberut Langurs, P. siberu) may be an adaptation to increased hunting and the need for increased vigilance. Adult males and females seem to share equal responsibility for leading group movements. Intragroup aggression is infrequent. Densities are c. 1 - 7 groups / km?. It is sympatric with the Pagai Macaque (Macaca pagensis), the Pigtailed Langur (Simias concolor), and Kloss’s Gibbon.

Sumber: Cercopithecidae

Status and Conservation. CITES Appendix I. Classified as Critically Endangered on The IUCN Red List (as P. potenziani potenziani). The Mentawai Langur is protected by Indonesian law. It is threatened by logging and hunting and is reported to be the second-most popular game species after the Pig-tailed Langur. On Siberut, where its sister taxon, the Siberut Langur, is found, local people are reported to climb up into their sleeping trees at night to shoot them; this hunting method may also be used for Mentawai Langurs. In recent years, hunting has intensified because of increased access to remote areas due to logging roads and tracks and the replacement of bows and arrows with rifles. Local rituals and taboos that formerly regulated hunting have been lost because of the Christian religion. Mentawai Langurs are occasionally kept as pets but do not thrive in captivity. Other threats include oil palm plantations, forest clearing, and product extraction by local people. Population decline of the Mentawai Langur is estimated at more than 50 % over the past 40 years. In 2005, the population was thought to number only 300 - 1200 individuals across the three islands. It is not found in any protected areas, but was present in the proposed Betumonga Research Area, which was logged by 2003. In 2006, the following conservation actions were suggested: protection of areas in the Pagai Islands by cooperating with a logging corporation that has practiced sustainable logging technique there since 1971; conservation education, especially regarding hunting; and the development of alternative economic models for the local people to reduce the likelihood of them selling off their lands to logging companies.

Sumber: Cercopithecidae