The golden-mantled tamarin (Leontocebus tripartitus) is a tamarin species from South America. It is found in Ecuador and Peru, specifically in the upper Amazon (lowland), east of the Andes in Ecuador, and Northeast Peru; between the Rio Curaray and Rio Napo in Peru. Taxonomic classification There has been some debate over the placing of L. tripartitus. In field observations in South America, scientists compared feeding habits and heights between golden-mantled tamarins (L. tripartitus) and brown-mantled tamarins (Leontocebus fuscicollis) and they concluded that patterns of height were very similar to those observed in L. fuscicollis. The similarity and the lack of evidence for sympatry with either L. fuscicollis or the black-mantled tamarin (Leontocebus nigricollis) led to the suggestion that L. tripartitus should be reconsidered as a subspecies of L. fuscicollis rather than a species on its own; alternatively, other subspecies of L. fuscicollis should be raised in taxonomic rank. It is currently considered a separate species within the saddle-back tamarin genus Leontocebus. Description This tamarin measures 218–240 mm from the tip of the nose to the beginning of the tail and has a tail length of 316–341 mm. Its ear length is 31–32 mm. The head is black, with a black collar of hair continuous under the throat. The muzzle and sometimes face are pure white, and the neck has a ruff of bright golden to creamy fur dorsally, sharply contrasting with the black crown. Its underparts are orange. The long tail is not prehensile, as in all tamarins, and the large eyes face forward. The species is monomorphic. It has large canines and claw-like nails on all digits except the opposable. Behavior The golden-mantled tamarin is an arboreal, diurnal species ranging through the understory, moving by quadrupedal walk and leap, mainly on small horizontal supports. Leaping is the main gap-crossing mode of locomotion, though it decreases in proportion with a higher use of the upper forest layers. It forages most actively between 4–10 meters off the forest floor, and eats mainly fruit, nectar and insects but also consumes gum from either natural holes or holes created by the pygmy marmoset. Due to its small body size, limited gut volume, and rapid rate of food passage, tamarins require a diet high in nutrient quality and available energy. Water accumulated on leaves, in flower cups, or in hollows is lapped; dew and moisture from a hand previously dipped in water are licked.