GRAND ETANG NATIONAL PARK, Grenada -- Several troops of mona monkeys (Cercopithecus mona) roam the forests of Grenada. Mona monkeys are not native to the Western Hemisphere, but instead were introduced from Africa. As members of the Cercopithecidae -- or Old World monkeys -- they do not have the prehensile tails characteristic of their New World cousins. This one kept watch on the parking lot at the visitor center at Grand Etang National Park.