Langur de Ha Tinh

activity

Activity patterns. Hatinh Langurs are diurnal, crepuscular, and terrestrial, but mainly arboreal. There are no studies of their activity patterns in the wild. Hatinh Langurs in a captive population at the Endangered Primate Rescue Center, Vietnam, spend an average of 72 % of the day resting, 23 % feeding, 3 % engaged in social behavior, and 2 % moving. Their time budget is very similar to closely related species occurring in the wild, except that individuals travel more in the wild. In Phong Nha-Ke Bang National Park, Hatinh Langurs return to the vicinity of their sleeping sites, on average 65 minutes before sunset. They forage and play until they enter their sleeping caves, c. 14 minutes after sunset. They leave their caves and crevices before dawn at 05: 00 - 05: 30 h.

Cercopithecidae

biology_ecology

Habitat. [Limestone karst with its typical vegetation. Hatinh Langurs prefer areas with dense forest cover. Dense forest is present in ¢. 90 % ofits known distribution. The core population occurs in one of the largest karst blocks in Indochina in Phong Nha-Ke Bang National Park in north-central Vietnam and Nakai-Nam Theun National Protected Area in east-central Laos. Caves and cliffs are used as sleeping sites, normally for many years if there is no disturbance or poaching. The heights of the caves or crevices on the cliffs vary from ¢. 20 - 60 m from their bases. Well-used sleeping sites are easily identified by the dark-yellow or brown stains on cliffs — marks of urine and feces.

Cercopithecidae

biology_ecology

Movements, Home range and Social organization. Quadrupedalism is the most frequent form of locomotion. The Hatinh Langur appears to be more arboreal than the other “ limestone langur ” species. Differing from Francois’s Langur, They hold their tails in a concave-upward inflection when walking and especially when running. In a large semi-wild, 20 ha area with natural vegetation, Hatinh Langurs spent 66 - 3 % of their time in trees, 17 - 7 % in scrub, 12: 4 % on fallen dead tree trunks, and 3: 6 % on rocks. There is no information about their home ranges in the wild. From 1995 to 1996, average group sizes of Hatinh Langurs in Phong Nha-Ke Bang National Park were 7 - 8 individuals. In 2007, average group size was 5 - 1 individuals (n = 23). Poaching may be the reason for the decrease. Groups normally have one male, three to four females, and their immature offspring. A group with 30 individuals has been seen.

Cercopithecidae

breeding

Breeding. Male Hatinh Langurs reach maturity at c ¢. 5 years old and females at c. 4 years. The gestation period is 180 - 190 days. Females give birth to a single offspring. Births occur throughout the year but peak in January-March.

Cercopithecidae