370.

Ucayali South American Spiny Mouse

Scolomys ucayalensis

French: Scolomys de |'Ucayali / German: Ucayali-Neuweltstachelmaus / Spanish: Raton espinoso de Ucayali

Other common names: Long-nosed Scolomys, Ucayali Spiny Mouse

Taxonomy. Scolomys ucayalensis Pacheco, 1991, right bank of the Rio Ucayali, 2-8 km east ofJenaro Herrera, Loreto, Peru.

Important variation in measurements among known samples of S. ucayalensis suggest it represents a species complex, but additional taxonomic research is needed to clarify this. Monotypic.

Distribution. Extreme S Colombia, E Ecuador, NE Peru, and W Brazil.

Descriptive notes. Head—body 88-114 mm, tail 60-78 mm, ear 13-15 mm, hindfoot 18-22 mm; weight 20-34 g. The Ucayali South American Spiny Mouse is small massivebodied and spiny. Dorsal fur is entirely of flattened spines. Dorsum varies from grizzled pale reddish brown to dark reddish black, finely streaked with black. Head is broad, and snout is short, with distinctly pointed. Ears are small and rounded. Tail is short (c.83% of head-body length) and nearly naked. Hindfoot is whitish, short and,relatively broad, with hypothenar pad greatly reduced or absent and thenar and interdigital pads well developed. Chromosomal complement of western Brazilian specimens is 2n = 50, FN = 68.

Habitat. Lowland rainforest, including primary and secondary forests, terra firma forest. In Ecuadorean localities, the Ucayali South American Spiny Mouse lives in mature subtropical rainforest dominated by Ficus trees ( Moraceae) and in cloud forest with trees 20 m high and covered by bryophytes and bromeliads.

Food and Feeding. No information.

Breeding. Pregnant Ucayali South American Spiny Mice with 1-3 embryos were recorded in August-March, spanning wet and dry seasons.

Activity patterns. The Ucayali South American Spiny Mouse is nocturnal and terrestrial.

Movements, Home range and Social organization. The Ucayali South American Spiny Mouse is solitary. It has been observed climbing fallen logs up to c.1 m.

Status and Conservation. Classified as Least Concern on The IUCN Red List.

Bibliography. Anderson, Gémez-Laverde &Tirira (2016b), Brito & Arguero (2012), Castro & Zapata-Rios (2001), Eisenberg & Redford (1999), Gémez-Laverde et al. (2004), Pacheco (1991), Pacheco et al. (2009), Patton (2015c¢), Patton & da Silva (1995), Patton et al. (2000), Tirira (2007).