(Macaca silenus), also wanderoo, a monkey having a body length of approximately 55 cm and a tail length of 25–35 cm. The dense hair is blackish or dark brown; the face is black and framed by a ruff of long grayish brown hairs, which form a light beard. The ruff is less pronounced in females than in males. The tail ends in downy tuft, similar to that of the baboon. The lion-tailed macaque inhabits the dense mountain forests of southwestern India. It lives in troops of about 20 individuals, usually in tall trees.