Visitors may also view a troop of hamadryas baboons, golden-bellied mangabeys, emperor tamarins, golden lion tamarins, red-handed tamarins, owl monkeys, wite-headed marmosets, pygmy marmosets.
Until 2001, most authorities included it as a subspecies (or simply a taxonomically insignificant variation) of the red-handed howler, though its distinction had already been pointed out much earlier.