Isothrix bistriata Wagner 1845
Creators: name: Don E. Wilson
name: Thomas E. Lacher, Jr
name: Russell A. Mittermeier
Publisher: name: Lynx Edicions
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Rodentia
Echimyidae
Isothrix
Isothrix bistriata

description: 57.
Yellow-crowned Brush-tailed Rat
Isothrix bistriata
French: Rat-épineux couronné / German: Zweistreifen-Borstenschwanzratte / Spanish: Rata de cola de cepillo de corona amarilla
Taxonomy. Isothrix bistriata Wagner, 1845,
“Rio Guapore.” Restricted by L. H. Emmons and J. L. Patton in 2015 to “Isla Leomil, Rio Guaporé, Beni, Bolivia.”
Isothrix bistriata includes Lasiuromys villosus named by M. E. Deville in 1852 and I. bistriata boliviensis named by F. Petter and H. Cuenca in 1982. Monotypic.
Distribution. W Amazon Basin in E Ecua-dor E Peru, W Brazil, and N Bolivia; prob-ably also in SE Colombia.
Descriptive notes. Head—body 214-275 mm, tail 215-271 mm; weight 300-530 g. The Yellow-crowned Brush-tailed Rat is one of the largest species of Isothrix, with soft, lax, and long fur. Dorsum is grizzled yellow-brown to olive, mixed with black hairs. Two conspicuous supraorbital black or brown stripes extend over head onto nape; these stripes surround pale creamy patch on rostrum and forehead. Color and intensity of creamy patch and its surrounding stripes increase with age. Compared with its congeners, the Orinoco Brush-tailed Rat (/. orinoct) and the Rio Negro Brush-tailed Rat (I. negrensis), black supraorbital stripes of the Yellow-crowned Brush-tailed Rat do not fuse behind head but remain separate. Venteris buff or pale yellow. Tail length is usually 87-6-108-6% of head-body length. Tail is entirely haired and golden or rust colored on basal one-third, usually becoming black distally. In some individuals, distal part may range from pale yellow to white. Chromosomal complement is 2n = 60 and FN = 116.
Habitat. Seasonally flooded floodplain forests (either igapo or varzea) at elevations of 100-250 m. Most specimens of Yellow-crowned Brush-tailed Rats have been obtained in traps placed in the canopy and a few directly from tree holes.
Food and Feeding. There is no information available for this species.
Breeding. Based on placental scars, Yellow-crowned Brush-tailed Rats have litters of 1-2 young. Pregnant females were caught throughout the year along Rio Jurua in Brazil. A lactating female was collected in August with a juvenile weighting 49 g. Presumably reproductively active adult males had enlarged testes averaging 24 x 12 mm and swollen vesicular glands ¢.25 mm in length.
Activity patterns. There is no information available for this species.
Movements, Home range and Social organization. Yellow-crowned Brush-tailed Rats are known to nest in holes on trunks of large trees, with pairs of adult observed at several different localities. They are vocal, and indigenous people have seen them calling from tree branches and entrances of their nest holes at night.
Status and Conservation. Classified as Least Concern on The IUCN Red List. As a rainforest species, Yellow-crowned Brush-tailed Rat might be affected by deforestation; however, it occurs in flooded forests that are not highly threatened habitats in the Amazonian region. Additional studies on distribution, habitat, abundance, ecology, and conservation threats to Yellow-crowned Brush-tailed Rat are needed.
Bibliography. Deville (1852), Eisenberg & Redford (1999), Emmons (1990, 1997a, 2005), Emmons & Patton (2015b), Patterson & Velazco (2006, 2008), Patton & Emmons (1985), Patton et al. (2015), Petter & Cuenca (1982), Tate (1935), Thomas (1899d, 1916b, 1924b, 1928a), Trouessart (1897), Upham et al. (2013), Wagner (1845), Woods (1993), Woods & Kilpatrick (2005).
description: Published as part of Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Echimyidae, pp. 552-604 in Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona :Lynx Edicions on page 583, DOI: 10.5281/zenodo.6623649