517.

Woolly Giant Rat

Kunsia tomentosus

French: Akodon laineux / German: Woll-Riesenratte / Spanish: Rata gigante lanuda

Other common names: Woolly Kunsia

Taxonomy. Mus tomentosus Lichtenstein, 1830, “waldigen Gegenden am Uruguay [= wooded areas of Uruguay].” Restricted by P. Hershkovitz in 1966 to the Rio Uruguay in south-eastern Brazil (probably state of Rio Grande do Sul).

Validity of subspecies principalis named by P. W. Lund in 1840 for speciments near [Lagoa Santa, Minas Gerais State, Brazil, is questioned. Monotypic.

Distribution. N & E Bolivia and C Brazil; it probably also occurs in extreme SE Peru.

Descriptive notes. Head—body 185-287 mm, tail 147-196 mm, ear 28-36 mm, hindfoot 43-54 mm; weight 241-630 g. The Woolly Giant Rat is the largest extant Sigmodontinae. It has dense and coarse fur, proportionally short limbs with large and powerful feet and claws, and moderately short tail (¢.65% of head-body length). Rhinarium is large and naked and highlighted by ring of whitish hair. Ears are small and round (c.13% of head-body length), and pinnae are covered with short hairs that match color of dorsal pelage. Tail is unicolored, scarcely covered with short rigid hairs, and has large subrectangular scales. General pelage is dark gray or dark brown on dorsal surface and grayish on gular and ventral surfaces. Eight mammae are arranged in pectoral, postaxial, abdominal, and inguinal pairs. Chromosomal complement is 2n = 44, FN = 42.

Habitat. Tropical savanna and grasslands from Cerrado and Beni Savanna biomes; two records are also known for Amazon savannas. The Woolly Giant Rat reportedly occurs almost exclusively in unflooded grasslands.

Food and Feeding. Direct field observations indicate that The Woolly Giant Rat eats roots of grasses. One captive individual ate insects ( Orthoptera and Isoptera) that were moving in leaflitter inside the vivarium where it was kept; insects were located by smell, captured with forefeet, and transferred to the mouth.

Breeding. Breeding of the Woolly Giant Rat might occur twice a year. A pregnant female was recorded in July (dry season) with three embryos; another pregnant female was captured in October (early wet season) with one embryo. Juveniles were caught in June-July and November.

Activity patterns. The Woolly Giant Ratis active day and night, semi-fossorial, and reportedly builds small galleries with grasses pulled up from the surrounding area.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Nevertheless, the Woolly Giant Rat suffered recent regional extinctions in south-eastern Brazil.

Bibliography. Anderson (1997), Andrades-Miranda et al. (1999), Bezerra (2005, 2015), Bezerra & Pardinas (2016), Bezerra et al. (2007), Emmons (1998), Hadler et al. (2016), Hershkovitz (1966a), Ibanez et al. (1994), Lichtenstein (1830), Lund (1840b), Marinho-Filho & Vieira (2016), Massoia & Fornes (1965d), Miranda-Ribeiro (1914), Pardinas, D'Elia & Teta (2009), Santos-Filho et al. (2001), Teran et al. (2008), Winge (1887).