Preuss's monkey

Preuss's monkey, Allochrocebus preussi, also called Preuss's guenon, is a diurnal Old World monkey that lives on the ground and in the lower levels of mountain forest, at elevations up to about 2,500 metres. Its range covers eastern Nigeria, western Cameroon and the island of Bioko in Equatorial Guinea. It was long treated as a subspecies of L'Hoest's monkey and, like that species, was moved from the genus Cercopithecus to Allochrocebus. The animal is darkish in colour with a white chin, and adult males have a blue scrotum. Individuals weigh up to about 10 kilograms. Troops hold one adult male with several females and young, averaging about 17 animals. Fruit, leaves and insects make up most of the diet, though the monkey sometimes raids human crops. Females bear a single young about every three years, and the species is listed as endangered because of habitat loss and hunting. Two subspecies are recognised, one in Cameroon and one on Bioko.