The coat on the lower surface of the body is white, on the rest of the body it is dark gray. Two white stripes on the forehead are connected downward, forming a semblance of the letter “V”. Eyes are orange-brown, skin is pink. The average weight of these primates is 6.67 kg for males and 6.69 kg for females. Body length from 420 to 620 mm, tail length from 500 to 850 mm. The digestive system is adapted to digest cellulose, which is rich in the diet of monkeys. Fangs of males are larger than fangs of females. The incisors are long and narrow. The muzzle is short and wide. The thumb is reduced. The hind limbs are longer than the front. [2] [3]
They are found in the north of Sumatra , Indonesia, in Aceh province, north of the Simpangkiri and Wampu rivers. [four]
Daytime animals, often descending to the ground from trees in search of food. Form groups of 3 to 20 individuals. A group usually consists of one male, several females and their offspring. In the diet, fruits, seeds, leaves, flowers, bark, sprouts, as well as small animals such as insects, lizards, bird eggs. There is no pronounced breeding season. Pregnancy lasts from 5 to 6 months. There is usually one cub in the litter. Until the age of 12 or 15 months, the young feed on mother's milk. Puberty occurs at the age of 4 to 5 years. [3]
The International Union for Conservation of Nature has assigned this species a “Vulnerable” conservation status since, according to 2008 estimates, the population has declined by more than 30% over 40 years (3 generations). The main threat to the population is habitat destruction. [5]
