25. Lesson’s Saddle-back Tamarin Saguinus fuscus French: Tamarin de Lesson / German: Brauner Sattelrlickentamarin / Spanish: Tamarin de Lesson Taxonomy. Leontocebus fuscus Lesson, 1840, “Plaines de Mocoa,” the lowlands of the Mocoa district, between the rios Putumayo and Caqueta, Putumayo, Colombia. Formerly considered a subspecies of S. fuscicollis but molecular genetic evidence indicates thatit is closer phylogenetically to S. nigricollis than S. fuscicollis, and sufficiently distinct as to warrant specific status. Monotypic. Distribution. SE Colombia and NW Brazil (Amazonas State), N of the Rio Solimoes between the rios Japura-Caqueta and Ica-Putumayo, W of the Rio Yari to the N of the Rio Caquetd, through the basin of the Rio Caguan, and lower parts of the Rio Orteguaza, W to the Andean foothills to 500 m above sea level. Descriptive notes. Head-body 22-9 cm (males) and 22-3 cm (females), tail 34-6 cm (males) and 35 cm (females); weight ¢.350-400 g. The crown, forehead, and cheeks of Lesson’s Saddle-back Tamarin are covered by black hairs. Facial skin is black, and there are short gray hairs around the mouth and sides of the nostrils. Hairs on the sides of the head beneath the ears are reddish brown to blackish brown. The mantle is orangebrown and evenly ticked with black hairs. The lower back (saddle) is marbled buffy and black. Arms, rump, and thighs are the same color as the mantle. Upper surface of hands and feet are blackish mixed with orange. The throat, chest, belly, and inner parts of limbs are rufous,lightly suffused with blackish or dark brown hairs. The tail is black with the ventral surface of the basal third being rufous. Habitat. Primary and secondary lowland rainforest. Lesson’s Saddle-back Tamarin prefers dense vegetation in secondary forest and tree falls, but it has not been studied in the wild. Food and Feeding. Lesson’s Saddle-back Tamarin eats small fruits, nectar, gums, and small animal prey. Breeding. There is no information available for this species. Activity patterns. There is no information available for this species. Movements, Home range and Social organization. There have been some observations on Lesson’s Saddle-back Tamarin near Mocoa on the Rio Caqueta and on an island in the Rio Guineo, Putumayo. They are found in groups of 5-10 individuals. They have been observed traveling with Goeldi’s Monkey (Callimico goeldii). A population survey in floodplain forest near the Quebradon el Ayo, Colombia, a small clearwater tributary south of the Rio Caqueta near the Brazilian border, found 16-9 ind/km* or 3 groups/km?®. Status and Conservation. CITES Appendix II. Classified as Least Concern on The IUCN Red Last (as S. fuscicollis fuscus). Lesson’s Saddle-back Tamarin is widespread and common. Although hunted to some extent for food and for pets,it is not threatened.Its status in Brazil is unknown. The Juami-Japura Ecological Station and the Mamiraua Sustainable Development Area are within its supposed geographic distribution in Brazil, but its presence there has not been confirmed. In Colombia, it occurs in La Paya and Cahuinari national natural parks. Bibliography. Cheverud (1995), Cheverud & Moore (1990), Cropp et al. (1999), Defler (1994b, 2003b, 2004), Hernandez-Camacho & Cooper (1976), Hernandez-Camacho & Defler (1985, 1989), Hershkovitz (1977), Moynihan (1976), Palacios & Peres (2005), Snowdon & Soini (1988).

Published as part of Russell A. Mittermeier, Anthony B. Rylands & Don E. Wilson, 2013, Callitrichiade, pp. 262-346 in Handbook of the Mammals of the World – Volume 3 Primates, Barcelona :Lynx Edicions on page 324, DOI: 10.5281/zenodo.5730714