Francois Langur

The Francois (pronounced frawn-SWAH) monkey, Presbytis francoisi, is one of several species sometimes called leaf monkeys because of their diet. Leaf monkeys have long limbs and tails, long slender hands and feet, and very short thumbs.Their faces are usually dark and without hair, and their muzzles are short. The hairs on their crowns are usually arranged in some form of crest or cap, and their abdomens bulge. They lack cheek pouches but have enlarged salivary glands which help them digest leaves.The pads on their buttocks, called ischial callosities, are separate in females, united as one in males.Francois monkey body lengths range from 20-26 inches, with 32-35 inch tails. They weigh about 13 pounds and have glossy black coats. They have prominent brow ridges resembling raised eyebrows. The white stripes that run from the corners of their mouths to their ears, and the pointed crests on their heads make them easily distinguishable. The young are bright apricot in color, contrasting with the black adults.DIET:Francois monkeys subsist mainly on leaves, both young and mature. Fruit, buds, flowers, seeds, stems and bark provide supplements. They drink very little water.BEHAVIOR:Leaf monkeys are active during the day and spend most of their time in trees. They are noisy animals that use both arms and legs to swing, leap, bounce and crash through tree branches.Mutual relaxed grooming is important in the social life of these primates and occupies up to five hours a day.Environmental factors greatly influence their social behavior by affecting group size, home range size, sex ratio, sexual behavior and vocalization.DISTRIBUTION AND HABITAT:Leaf monkeys are widely distributed through the Indian subcontinent, Burma and China, and southward through Indo-China and Malaya to Sumatra, Java and Borneo. They occupy a wide variety of ecological habitats.Francois monkeys are native to northeast Vietnam, southeastern China and west-central Laos, where they inhabit tall riverside crags in tropical monsoon forest in limestone mountains.REPRODUCTION and GROWTH:Single births are usual, following a gestation period of about 200 days. The infant may nurse for up to two years, but once weaned, it ceases to have contact with its mother.Females become sexually mature at 3-4 years and males at four years of age. Physical growth is not complete until 6-7 years, however.NOTE:White-sideburned black leaf monkey, Francois langur and Francois's black leaf monkey are other names for this animal. It is endangered because of habitat loss and hunting by people who believe its parts have medicinal value.