28. Andean Saddle-back Tamarin Saguinus leucogenys French: Tamarin des Andes / German: Anden-Sattelriickentamarin / Spanish: Tamarin andino Taxonomy. Midas leucogenys Gray, 1866, Brazil. Restricted by P. Hershkovitz in 1966 to the Department of Huanuco, Peru. Formerly considered a subspecies of S. fuscicollis. Molecular genetic analysis found intergradation between the darkbrown mantled S. illiger: and the blackermantled S. leucogenys in the San Martin area in Moyobamba and the Rio Mayo Valley, where S. leucogenys looked more similar to S. ulligeri than along the Rio Ucayali and Rio Tapiche. Phenotypic similarity was reflected in the their mitochondrial data—all individuals in the northern part of the distribution of S. leucogenys formed a well-supported clade with S. illigeri, but all individuals from the southern part ofthe distribution ofleucogenys fell into a clade that included the southern saddle-back tamarins S. wedddelli, S. fuscicollis, S. nigrifrons, and S. melanoleucus. The southern population has the very dark mantle seen in the leucogenys type. The split ofthe northern and southern populations ofleucogenys (either side ofthe Rio Pachitea) indicates the need for more research and a reassessment ofthe taxonomy. Monotypic. Distribution. NC Peru, from S of Rio Maranon, from San Martin through Huanuco and Pasco to the Rio Perené, N Junin, E to W ofthe Rio Huallaga and the upper Rio Ucayali, and S ofthe Rio Pisqui; probably not above elevations of 900-1000 m. Descriptive notes. Head-body 20-5-23 cm, tail 30-5-33 cm; weight ¢.350-400 g. The head, mantle, forelimbs, throat, and upper part of the chest of the Andean Saddleback Tamarin are dominantly black or blackish brown, sometimes agouti. The front of the thigh, otherwise orange, usually has a dark patch, and, unlike Weddell’s Saddleback Tamarin (S. weddellr), there is no white blaze on the forehead between the eyes. Outersides ofthe arms are like the mantle, but slightly more ticked with orange. The saddle is marbled buffy and black. The rump is orange. Upper surface of hands and feet are black. The lower chest, belly, and inner sides ofthighs are reddish, washed or lined with black. The tail is black, except for a reddish part at the base. External genitalia are mostly or entirely black. Habitat. High-elevation forests up to 900-1000 m above sea level along the eastern base of the Andean range. In the Panguana Biological Station, the Andean Saddleback Tamarin has been seen in primary forest, secondary forest, forest edge, and riveredge (riparian) forest, and around plantations and human habitation. Food and Feeding. The Andean 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 is no information available for this species. Status and Conservation. CITES Appendix II. Classified as Least Concern on The [UCN Red List (as S. fuscicollis leucogenys). The Andean Saddle-back Tamarin is endemic to the Peruvian Amazon. It is common in the Pucallpa area to the west of the Rio Ucayali. It occurs in Tingo Maria National Park, Yanachaga Chemillén National Park, probably low-lying parts of Alto Mayo Protection Forest, and Panguana Biological Station in the southern part ofits distribution. Other protected areas within its distribution include Yanesha Communal Reserve, San Matias-San Carlos Protection Forest, and Pui-pui Protection Forest, but there is no information as to whether they actually occur there. It has not been recorded in Rio Abiseo National Park, probably because of its high elevation. Bibliography. Aquino & Encarnacion (1994b), Freese et al. (1982), Hershkovitz (1966, 1977), Hutterer et al. (1995), Matauschek et al. (2011), Snowdon & Soini (1988), Soini et al. (1989).

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 325, DOI: 10.5281/zenodo.5730714