any of three colourful species of langur monkeys found in the tropical forests of central and southern Vietnam, southern Laos, and northeastern Cambodia. Doucs are among the most strikingly coloured primates. The head is brownish, but the body appears blue-gray owing to black-and-white bands on each hair. The tail and long cheek whiskers are white, as are the rump patch and the throat, which is bordered by a necklacelike red line. The vivid orange-yellow face has slanting, almond-shaped eyes. Doucs grow to more than a half metre (20 inches) long, not including the tail, which is slightly longer than the body. Males weigh 11 kg (24 pounds), females about 8.5 kg.
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