Echimyidae Author Don E. Wilson Author Thomas E. Lacher, Jr Author Russell A. Mittermeier text 2016 2016-07-31 Lynx Edicions Barcelona Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I 552 604 book chapter 67690 10.5281/zenodo.6623649 5be7e52f-9b9c-4c03-99ed-f346bbcde1d0 978-84-941892-3-4 6623649 81. Dark Tree-rat Echimys saturnus French: Rat-épineux noir / German: Dunkle Stachelratte / Spanish: Rata arboricola oscura Other common names: Dark Spiny Tree-rat Taxonomy. Echimys saturnus Thomas, 1928 , “Rio Napo, Oriente of Ecuador. Alt. 3300" [= 1005 m].” This species is monotypic. Distribution. E Andean foothills and adjacent Amazonian lowlands in E Ecuador and N Peru. Descriptive notes. Head-body 272-335 mm, tail 295-383 mm. No specific data are available for body weight. The Dark Tree-rat is medium-sized, with glossy dorsal fur of brown tones that contains abundant bristles, with flat spines on mid-back but not over rump. Head and mid-back have typical glossy black color. Under parts are white, white-spotted, or whitish with buff tinge; chin is dark. Tail is ¢.140% of headbody length and densely haired from base to tip. Tail is longitudinally bicolored, with its base glossy black and distal white part of varying length. Ears are short and covered by hairs of head. Hindfeet are brown above, with strong claws on each digit. Some melanistic specimens have been reported in museum collections. Habitat. Pre-montane and lowland rainforest at elevations of 230-1005 m. Dark Treerats have been camera-trapped on the ground along stream edges, both partially in water or moving either toward or away from a water channel. Food and Feeding. There is no specific information available for this species, but the Dark Tree-rat is likely folivorous—frugivorous and might also include insects in its diet, as do other species of Echimys . Breeding. Female Dark Tree-rats have been found with two embryos. Activity patterns. There is no specific information available for this species, but the Dark Tree-rat appears to be strictly nocturnal. Movements, Home range and Social organization. Dark Tree-rats were camera-trapped nine times during 297 nights at one locality in Ecuador. Pictures showed eightsolitary individuals and a group ofthree individuals. Potential solitary habits are similar to that of the White-faced Tree-rat ( E. chrysurus ). The group of three individuals might have been a female with two young moving together, apparently in a straight line by following the white-tippedtail of the leading individual. Status and Conservation. Classified as Data Deficient on The IUCN Red List. Additional ecological studies of the rare Dark Tree-rat, an Andean endemic, are needed to assess its conservation status. Bibliography. Blake et al. (2010), Eisenberg & Redford (1999), Emmons (1990, 1997a, 2005), Emmons & Stark (1979), lack-Ximenes et al. (2005), Patton et al. (2015), Thomas (1928a), Woods (1993), Woods & Kilpatrick (2005).